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Computer Analysis of Amino Acid ChromatographyHayes, Michael D. 05 1900 (has links)
The problem with which this research was done was that of applying the IBM360 computer to the analysis of waveforms from a Beckman model 120C liquid chromatograph. Software to interpret these waveforms was written in the PLl language. For a control run, input to the computer consisted of a digital tape containing the raw results of the chromatograph run. Output consisted of several graphs and charts giving the results of the analysis. In addition, punched output was provided which gave the name of each amino acid, its elution time and color constant. These punched cards were then input to the computer as input to the experimental run, along with the raw data on the digital tape. From the known amounts of amino acids in the control run and the ratio of control to experimental peak area, the amino acids of the unknown were quantified. The resulting programs provided a complete and easy to use solution to the problem of chromatographic data analysis.
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Protein Design and Engineering Using the Fluorescent Non-canonical Amino Acid L-(7-hydroxycoumarin-4-yl)ethylglycineJanuary 2020 (has links)
abstract: Proteins are, arguably, the most complicated molecular machines found in nature. From the receptor proteins that decorate the exterior of cell membranes to enzymes that catalyze the slowest of chemical reactions, proteins perform a wide variety of essential biological functions. A reductionist view of proteins as a macromolecular group, however, may hold that they simply interact with other chemical species. Notably, proteins interact with other proteins, other biological macromolecules, small molecules, and ions. This in turn makes proteins uniquely qualified for use technological use as sensors of said chemical species (biosensors). Several methods have been developed to convert proteins into biosensors. Many of these techniques take advantage of fluorescence spectroscopy because it is a fast, non-invasive, non-destructive and highly sensitive method that also allows for spatiotemporal control. This, however, requires that first a fluorophore be added to a target protein. Several methods for achieving this have been developed from large, genetically encoded autofluorescent protein tags, to labeling with small molecule fluorophores using bioorthogonal chemical handles, to genetically encoded fluorescent non-canonical amino acids (fNCAA). In recent years, the fNCAA, L-(7-hydroxycoumarin-4yl)ethylglycine (7-HCAA) has been used in to develop several types of biosensors.
The dissertation I present here specifically addresses the use of the fNCAA L-(7-hydroxycoumarin-4-yl)ethylglycine (7-HCAA) in protein-based biosensors. I demonstrate 7-HCAA’s ability to act as a Förster resonance energy transfer (FRET) acceptor with tryptophan as the FRET donor in a single protein containing multiple tryptophans. I the describe efforts to elucidate—through both spectroscopic and structural characterization—interactions within a 7-HCAA containing protein that governs 7-HCAA fluorescence. Finally, I present a top-down computational design strategy for incorporating 7-HCAA into proteins that takes advantage of previously described interactions. These reports show the applicability of 7-HCAA and the wider class of fNCAAs as a whole for their use of rationally designed biosensors. / Dissertation/Thesis / Doctoral Dissertation Biochemistry 2020
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Solid-Phase Synthesis of N-Carboxyalkyl Unnatural Amino AcidsFischer, Lindsey Gayle 09 March 2011 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / A novel route has been developed for the solid-phase synthesis of N-carboxyalkyl unnatural amino acids as potential metalloprotease inhibitors. The key step involves a nitrogen alkylation of resin-bound amino acids with -bromoesters. Alkylation of the benzophenone imine of glycine on Wang resin was used to introduce unnatural amino acid side chains onto the resin-bound glycine. The benzyl -bromoesters [BrCH(R2)CO2Bn], starting materials for the C-N bond construction, were prepared in solution by diazotization of naturally-occurring amino acids to form the -bromoacids, followed by benzylation of the carboxylic acid to form the benzyl -bromoesters. N-Alkylation of the resin-bound, unnatural amino acids with the benzyl -bromoesters and subsequent cleavage from resin gave the benzyl ester monoacid intermediates. Exploration of reverse-phase cyano-silica gel chromatography and preparative liquid chromatography provided effective purification of the benzyl ester intermediates. Hydrolysis of the analytically pure benzyl ester monoacids afforded clean products as the diacids. The two points of variation introduced through the two on-resin alkylation steps, C-alkylation of the benzophenone imine of glycine and N-alkylation with the benzyl -bromoesters, allow for the combinatorial synthesis of a library of target compounds.
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Amino acid content of commercial broiler rationsScheid, Harold Edward. January 1948 (has links)
Call number: LD2668 .T4 1948 S35 / Master of Science
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Strategies to control bacteriophage infection in a threonine bioprocessCele, Nolwazi January 2009 (has links)
Submitted in partial fulfillment of the academic requirements for the degree of Master of Technology: Biotechnology, 2009. / Production of numerous biotechnologically-important products such as
threonine is based on cultivation of bacterial cultures. Infection of these
bacterial cultures by bacteriophages has a detrimental effect in the production
of these bioproducts. Despite this, most people controlling these bioprocesses
do not recognize the early signs of bacteriophage infection. SA Bioproducts
(Ply) Ltd was no exception and has suffered tremendous loss of production
time after bacteriophages infected threonine producing E. coli strain B. This
study was aimed at developing assays to control and prevent bacteriophage
infection at this company. These included determining the source of phages
by monitoring the process plant environment, optimising the detection and
enumeration methods so as to monitor the levels of bacteriophages in the
environment, identification of bacteriophages in order to determine the
number of bacteriophages capable of infection threonine producing E. coli
strain B, treatment and of phages, and possible prevention of phage infection.
Adam's DAL method was very efficient at detecting phages in the samples
collected at various areas (sumps, odour scrubber, process water, and soil)
around the plant for 16 weeks. High levels of phages were found in the sumps
and this was identified as the source of infection. Samples collected were
grouped together according to their source. The samples were enriched and
purified in order to characterise them. The prevalent phage in all samples was
identified as a T1-like phage. Bacterial strains that grew on the plate in the
presence of phages were assumed to be resistant to phages or contained
lysogenic phages which would explain the new lytic cycles that were observed
whenever these resistant strains were used for production. UV light, green
v
indicator plates, and a mutagen (Mitomycin C) were used to detect Iysogens.
Mitomycin C at 1 IJg/ml was found to be most effective in detecting lysogenic
phages. This was shown by new plaque forming units that were visible on the
DAL plates. Temperature (heat), chemicals, and inhibitors (vitamins) were
investigated as strategies for prevention and treatment of bacteriophage
infection. Bacteriophage samples were exposed to 70, 80, 100, and 120°C. At
these temperatures pfu counts in the samples were reduced significantly. At
120°C there was a complete inactivation of bacteriophages within 30 minutes.
Chemicals investigated such as sodium hydroxide and Albrom 100T were
capable of complete deactivation of bacteriophages at a very low
concentration (0.1%). Therefore, these chemicals can be used to clean the
plant area and sumps. Vitamins C, K and E solutions were investigated to
determine their inhibitory effect on bacteriophages. Vitamin C, K and E
reduced pfu counts by 3, 2, and 4 logs, respectively. Therefore vitamin C and
E solutions were mixed and to determine if mixing them would enhance their
inactivation capabilities. This resulted in a reduction greater than 9 logs of
phage in the sample (from 7.7 x 109 to 3 pfu/ml). The host bacterium was also
exposed to this mixture to determine effect of the vitamin mixture on its
growth. It was found that there was no effect exerted by this mixture on the
host bacteria. This proved to be an ideal mixture for combating phages during
fermentation. However, vitamin E is not cost effective for co-feeding in 200 m'
fermenters, and therefore vitamin C solution was a cost-effective alternative. It
was concluded that bacteriophage contaminated bioprocessing plant should
be properly cleaned using a combination of heat and chemicals.
Bacteriophage infection should be prevented by employing inhibitors.
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Comparison of free amino acid profiles in carrot cell suspension cultures resistant to stress conditions.Alyousuf, Saeed Habib Hassan. January 1989 (has links)
Plant cells resistant to specific amino acid analogs have been reported to accumulate the corresponding free amino acids. The purpose of this study was to determine the concentrations of fifteen free amino acids: alanine, valine, leucine, isoleucine, glutamate, proline, arginine, aspartate, threonine, methionine, lysine, serine, glycine, tryptophan and phenylalanine in Daucus carota cell lines, resistant either to the proline analog azetidine-2 carboxylic acid (A2C), or to the tryptophan analog 5-methyltryptophan (5-MT), or to both the analogs combined. This study also intended to determine if these analogs influence the biosynthesis of the above-mentioned fifteen amino acids in the cell line resistant to A2C and 5-MT. Carrot cell lines resistant to 5-MT, to A2C, or to both the analogs were selected by incubating carrot cells in liquid growth media containing either 0.3 mM 5-MT, or 0.5 mM A2C for 6 to 16 weeks. Free amino acid concentrations were then determined in the extracts of the cells. Resistance to 5-MT resulted in significant increases in the intracellular concentrations of tryptophan, phenylalanine, leucine, valine, isoleucine, and proline. Resistance to A2C resulted in significant increase in proline only. Resistance to both the analogs caused increases in proline, lysine, phenylalanine, and tryptophan concentrations. In the cell line resistant to both the analogs, the treatment with 5-MT caused increases in leucine, proline, aspartate, threonine, lysine, and tryptophan. The treatment with A2C caused increases in isoleucine, arginine, threonine, methionine, lysine, and glycine, whereas treatment with both the analogs caused increases in threonine, lysine, phenylalanine, and tryptophan. These results indicate the possibility of a common biosynthetic control of a number of amino acids in carrot cells, resembling that found in microorganisms. It is also evident from the results that the analogs play an active role in the biosynthesis of amino acids in the resistant cell lines.
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Adenovirus-host interactions : implications for tropism and therapyLenman, Annasara January 2016 (has links)
Human adenoviruses (HAdVs) are common viruses often associated withgastrointestinal, ocular and respiratory infections. They can infect a widevariety of cells, both dividing and non-dividing. HAdVs attach to and infecttarget cells through interactions with cellular receptors. It has also beenshown that HAdVs can use soluble host components in body fluids forindirect binding to target cells, a feature that enables the usage of new typesof receptors resulting in a more efficient HAdV infection. We thereforeevaluated the influence of soluble components from four different bodyfluids on HAdV infection of epithelial cells, representing the respiratory andocular tropism of most HAdVs. We found that plasma, saliva, and tear fluidpromote binding and infection of HAdV-5 (species C) and that plasmapromotes infection of HAdV-31 (species A). Further binding and infectionexperiments identified coagulation factor IX (FIX) and X (FX) as thecomponents of plasma responsible for increase of HAdV-5 infection whileFIX alone mediates increase of HAdV-31 infection. We found that as little as1% of the physiological concentration of these factors is required to facilitatemaximum binding. The effect of coagulation factors on HAdV infection was thereafterextended to include all species A HAdVs: HAdV-12, -18 and -31. Species AHAdVs normally cause infections involving the airways and/or the intestine.These infections are often mild but species A HAdVs in general, and HAdV-31 in particular, have been shown to cause severe and life-threateninginfections in immunocompromised patients. We show here that FIXefficiently increase HAdV-18 and -31 (but not HAdV-12) binding andinfection of human epithelial cells, representing the respiratory andgastrointestinal tropism. FIX was shown to interact with the hexon proteinof HAdV-31 and surface plasmon resonance analysis revealed that theHAdV-31:FIX interaction is slightly stronger than that of the HAdV-5:FIX/FX interactions, but more interestingly, the half-lives of theseinteractions are profoundly different. By performing binding and infectionexperiments using cells expressing specific glycosaminoglycans (GAGs) and ivGAG-cleaving enzymes we found that the HAdV-31:FIX and HAdV-5:FIX/FX complexes bind to heparan sulfate-containing GAGs on targetcells, but we could also see a difference in GAG dependence and specificitybetween these complexes.We conclude that the use of coagulation factors might be of moreimportance than previously recognized and that this may affect not only theliver tropism seen when administering adenovirus vectors into thecirculation but also regulate primary infections by wild-type viruses of theirnatural target cells. We also believe that our findings may contribute tobetter design of HAdV-based vectors for gene and cancer therapy and thatthe interaction between the HAdV-31 hexon and FIX may serve as a targetfor antiviral treatment. HAdV vectors are mainly based on HAdV-5 and several problems haverecently become evident when using these vectors. Major challenges withHAdV-5 based vectors include pre-existing neutralizing antibodies, pooraccess to the receptor CAR (coxsackie and adenovirus receptor), and offtarget effects to the liver due to interactions with coagulation factors. Theneed for new HAdV vectors devoid of these problems is evident.HAdV-52 is one of only three HAdVs that are equipped with two differentfiber proteins, one long and one short. We show here, by means of bindingand infection experiments, that HAdV-52 can use CAR as a cellular receptor,but that most of the binding is dependent on sialic acid-containingglycoproteins. Flow cytometry, ELISA and surface plasmon resonanceanalyses revealed that the terminal knob domain of the long fiber (52LFK)binds to CAR, and the knob domain of the short fiber (52SFK) binds tosialylated glycoproteins. X-ray crystallographic analysis of 52SFK in complexwith sialic acid revealed a new sialic acid binding site compared to otherknown adenovirus:glycan interactions. Moreover, glycan array analysisidentified α2,8-linked oligosialic acid, mimicking the naturally occurringpolysialic acid (PSia), as a potential sialic acid-containing glycan receptor for52SFK. ELISA and surface plasmon resonance confirmed the ability of52SFK to interact with PSia. Flow cytometry analysis also showed a fivefold vincrease in binding of 52SFK to PSia-expressing cells compared to controlcells. X-ray crystallographic analysis of 52SFK in complex with oligo-PSiarevealed engagement at the non-reducing end of oligo-PSia to the canonicalsialic acid-binding site, but also suggested the presence of a 'steering rim'consisting of positively charged amino acids contributing to the contact bylong-range electrostatic interactions. PSia is nearly absent on cells in healthy adults but can be expressed inhigh amounts on several types of cancers including: glioma, neuroblastomaand lung cancer. We show here that the short fiber of HAdV-52 bindsspecifically to PSia. Taking into account that HAdV-52 has a supposedly lowseroprevalence and is incapable of interacting with coagulation factors webelieve that HAdV-52 based vectors can be useful for treatment of cancertypes with elevated PSia expression.
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Amino acid requirements of feedlot cattle according to the duodenal and whole empty body essential amino acid profileErasmus, Morné 12 1900 (has links)
Thesis (MScAgric)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: The purpose of this study was to determine the essential amino acid requirements of
beef cattle under feedlot conditions through evaluation of the duodenal and whole empty
body essential amino acid compositions. To define the ideal protein required for growth,
the whole empty body essential amino acid compositions of 8 beef steers (Simmental
and Hereford crosses) was investigated. The amino acid composition of the components
(carcass, metabolic organs and residual fraction), was pooled relative to their respective
mass and protein contribution, resulting in the calculated whole empty body amino acid
composition: arginine 6.81; histidine 2.69; isoleucine 4.02; leucine 6.96; lysine 7.43;
methionine 2.01; phenylalanine 4.03; threonine 4.01; valine 5.30; tryptophan 0.82.
Variations in profiles were found between scientific reports, either indicating that ratios
change with growth and implants or possibly through genotype.
The present study's body amino acid ratios were used to estimate dietary amino acid
requirements through evaluation of the duodenal essential amino acid compositions from
three different maize based feedlot diets. Although there was a general increase in the
biological value of protein after rumen fermentation, the duodenal essential amino acids
in comparison with the whole empty body recorded deficient/unbalanced profiles of
essential amino acids for growth. The chemical scores suggested that the first-to-thirdlimiting
amino acids in the duodenal digesta of beef cattle, that received three different
commercially available feedlot diets, were: histidine, lysine, methionine/arginine (Diet 1),
histidine, arginine, lysine (Diet 2) and arginine, methionine, histidine (Diet 3). Thedisproportionate duodenal amino acid concentrations obtained from the three diets,
emphasise the necessity to enhance the intestinal delivery of amino acid profiles through
different undegradable protein sources, with the objective to maximise protein utilisation
and obtain the genetic potential for optimal growth in feedlot cattle.
When amino acid requirements and flows to the duodenum were simulated using the
Cornell Net Carbohydrate and Protein system (CNCPS), predictions indicated that lysine
amino acid flow was limiting the metabolizable allowable average daily gain in Diet 1 and
3. Predicted profiles indicated that the order of limitation was: lysine, arginine, histidine
(Diet 1), lysine, arginine, histidine, methionine (Diet 2) and lysine, arginine, histidine (Diet
3). The predicted profiles were in accordance with observed duodenal values, except for
methionine that was observed limiting in Diet 1 and 3; however, the sequence and extent
of limitation varied. Results indicate that prediction models have potential in predicting
requirements; however there are still limitations for use to accurately define
requirements for particular EAA's.
From the present study, it is clear that the protein accretion was constrained by quantity
and/or disproportionality of amino acids available for absorption. Further research should
therefore be directed towards obtaining a more desirable array of amino acids to the
lower digestive tract that is digestible, absorbable and an economically viable option for
the feedlot operator. / AFRIKAANSE OPSOMMING: Aminosuurbehoeftes van Voerkraalbeeste Volgens die
Duodenale en Totale Lee Liggaam Essensiele Aminosuur
Profiel: Die doel van hierdie studie was om die essensiele aminosuur vereistes van vleisbeeste
onder voerkraal toestande te bepaal deur die evaluering van die duodenale en totale lee
liggaam essensiele aminosuursamesteilings. Om die idea Ie proteiene wat vir groei
benodig word te definieer, is 'n ondersoek ingestel na die totale lee liggaam essensiele
aminosuursamesteilings van 8 vleisbees osse (Simmetailer en Hereford kruise). Die
aminosuursamesteiling van die komponente (karkas, metaboliese organe en residuele
fraksie), se massa en proteien bydrae is gebruik om die totale lee liggaam
aminosuursamestelling 5005 volg te bereken: arginien 6.81; histidien 2.69; isoleusien
4.02; leusien 6.96; lisien 7.43; metionien 2.01; fenielalanien 4.03; treonien 4.01; valien
5.3; triptofaan 0.82. Variasies in profiele tussen wetenskaplike verslae is gevind. Dit dui
daarop dat groei en inplantings of moontlik genotipe 'n invloed op profiele kan he.
Die huidige studie se liggaam aminosuurverhoudings is gebruik om die dieet
aminosuurbehoeftes te skat deur evaluering van die duodenale essensiele
aminosuursamesteilings van drie verskiilende mielie-gebaseerde voerkraal diete.
Alhoewel daar 'n algemene toe name in die biologiese waarde van die proteien na
rumen fermentasie was, het die duodenale essensiele aminosure in vergelyking met die
totale lee liggaam, ongebalanseerde profiele van essensiele aminosure vir groei getoon.
Die chemiese teilings toon aan dat die eerste-tot-derde-beperkende aminosure in die
duodenale inhoud van vleisbeeste wat drie verskillende kommersieel beskikbare
voerkraal diete ontvang het, soos volg is: histidien, lisien, metionieniarginien (Dieet 1), histidien, arginien, lisien (Dieet 2) en arginien, metionien, histidien (Dieet 3). Die
ongebalanseerde aminosuur konsentrasies wat in die duodenum van die drie dlete
verkry is, beklemtoon die noodsaaklikheid om die intestinale lewering van
aminosuurprofiele te verbeter deur verskillende nie-degradeerbare proteien bronne te
voer. Die doelwit moet wees om proteien verbruik te optimaliseer en daardeur die
genetiese potensiaal vir optimale groei in voerkraalbeeste te bereik.
Met die simulering van aminosuurbehoeftes en vloei na die duodenum van die drie
standaard voerkraal diete met behulp van die "Cornell Net Carbohydrate and Protein
System" (CNCPS), het voorspellings gewys dat lisien aminosuurvloei die
metaboliseerbare toelaatbare gemiddelde daaglikse toename in Dieet 1 en 3 beperk het.
Voorspelde profiele wys dat die volgorde van beperking soos volg sou wees: lisien,
arginien, histidien (Dieet 1), lisien, arginien, histidien, metionien (Dieet 2)' en lisien
arginien, histidien (Dieet 3). Die voorspelde profiele was in ooreenstemming met die
waargeneemde duodenale waardes, behalwe vir metionien wat beperkend was in Dieet
1 en 3; die volgorde en mate van beperking was egter verskillend. Resultate wys dat
voorspellingsmodelle die potensiaal het om behoeftes te voorspel. Vir die akkurate
definisie van behoeftes vir spesifieke essensiele aminosuure is daar egter nog
beperkinge.
Uit die huidige studie, is dit duidelik dat protetenneerleqqinq deur die hoeveelheid en/of
oneweredigheid van geabsorbeerde aminosure beperk is. Verdere navorsing moet dus
fokus op die verkryging van In meer geskikte profiel van aminosure wat verteerbaar,
opneembaar en 'n ekonomiese lewensvatbare opsie vir die voerkraalbestuurder is.
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The essential amino acid requirements of springbok, blesbok and impala for optimal growthVan Zyl, Liana 12 1900 (has links)
Thesis (MScAgric)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: Regardless of the extensive game eradication during most of the previous century, the
game farming industry in South Africa has shown dynamic growth over the past few
decades. Currently the approximately 8 000 game farms have a total income of more
than R850 million per annum. Although there are various game species included in
these farming enterprises, three of the most important species for commercial farming
and meat marketing are springbok iAntidorcas marsupialisï, blesbok (Damaliscus
dorcas phillipsiï and impala (Aepyceros melampus).
Since nutrition is a key factor in the productivity of animals, any information on this
subject is essential for the successful management of a game farm. However, apart
from the general lack in applied research on game animals (due to the different
approaches by biologists and agricultural researchers), there is also only limited
information available on the nutritional requirements of game species or any of the
aspects affected by nutrition.
In order to address the above shortcomings in game animal nutrition, two separate
studies were conducted. The purpose of the first study was to determine the physical
body component and nitrogen (N) distribution in the springbok, blesbok and impala.
The chemical composition of the three-rib cut was also compared with that of the carcass. Amino acid requirements for growth of the three game species were
investigated in the second study according to the ideal protein concept. The essential
amino acid (EAA) profile of the whole empty body of the three game species was
compared with the EAA profile of the duodenal digesta in order to detect any
imbalances for optimal growth.
The same animals were used in both studies, namely eight of each of the three game
species. Characterization of the physical body composition revealed that the dressing
percentages (% of body weight; % of empty body weight) for the three game species
were: springbok (57.1 ± 2.4 %; 64.0 ± 2.5 %), blesbok (50.2 ± 2.1 %; 62.8 ± 1.4 %)
and impala (57.4 ± 2.2 %; 65.6 ± 2.0 %). The proportional distribution ofN between
the carcass, external offal and internal offal was also determined. The mean carcass N
concentration of the impala was higher (P<0.05) than that of the springbok and
blesbok on a dry matter basis. According to the carcass chemical composition, the
three game species seem to have a better potential for lean meat production (fat
content of carcass 4.7-5.2 %) than domestic sheep (17-25 % fat). Male animals had a
lower (P<0.05) fat and higher (P<0.05) moisture percentage in the carcass and threerib
cut than the females. The fat correlation between the three-rib cut and the carcass
on both an as-is and dry matter basis was significant across species and sexes. The
protein content of the same cuts did, however, not yield a significant correlation on an
as-is basis, and only the protein content of the springbok three-rib cut related (P<0.05)
to that in the carcass on a dry matter basis.
The second study concentrated on the nutritional requirements of springbok, blesbok
and impala, and more specifically the EAA requirements. Differences (P<0.05) were
found between the whole empty body EAA composition of the three game species.
These differences were present whether protein quantity was included in the
calculations (g AA/100 g crude protein) or not (expressed as % of lysine). The
chemical scores indicated that the four most limiting amino acids (three for impala) in
the duodenal digesta for whole empty body growth were: arginine, histidine,
threonine and methionine (springbok); methionine, arginine, histidine and lysine
(blesbok); and methionine, histidine and arginine (impala). Further disproportion of
the amino acids in the duodenal digesta was present in excess levels of isoleucine
(blesbok) and lysine, valine, leucine, threonine, isoleucine and phenylalanine (impala). The EAA:Lysine ratios of the whole empty body indicated a similar trend
for the three game species. / AFRIKAANSE OPSOMMING: Die essensiële aminosuurbenodighede van springbok,
blesbok en rooibok vir optimale groei: Ten spyte van die feit dat wild grootskaals uitgedun is gedurende die vorige eeu, het
die wildboerdery-bedryf in Suid-Afrika oor die laaste paar dekades dinamiese groei
getoon. Die totale inkomste van die ongeveer 8000 wildsplase beloop tans meer as
R850 miljoen per jaar. Alhoewel daar verskeie wildspesies is wat by hierdie tipe
boerdery ingesluit word, is die springbok (Antidorcas marsupialis), blesbok
(Damaliscus dorcas phillipsi) en rooibok (Aepyceros melampus) van die belangrikste
spesies vir kommersiële boerdery en vleisbemarking.
Voeding IS 'n sleutelfaktor in die produktiwitieit van diere en daarom is emge
inligting oor hierdie onderwerp noodsaaklik vir die suksesvolle bestuur van 'n
wildsplaas. Afgesien van die algemene tekort aan toegepaste navorsing op wilde diere
(as gevolg van die verskillende benaderings van bioloë en landboukundige navorsers),
is daar ook slegs beperkte inligting beskikbaar oor die voedingsbehoeftes van wilde
dierspesies of enige van die faktore wat deur voeding beïnvloed word.
In 'n poging om bogenoemde tekortkominge in die voeding van wilde diere aan te
spreek, is daar twee aparte studies uitgevoer. Die doel van die eerste studie was om
die fisiese liggaamsamestelling en die stikstof (N) verspreiding in die springbok,
blesbok en rooibok te bepaal. Die chemiese samestelling van die drie-ribsnit is ook met die van die karkas vergelyk. In die tweede studie is ondersoek ingestel na die
aminosuurbehoeftes van die drie wildspesies deur van die ideale proteïen konsep
gebruik te maak. Die bepaling van die essensiële aminosuurprofiel van die totale leë
liggaam van die onderskeie drie wildspesies is bepaal en met die essensiële
aminosuurprofiel van die duodenale-inhoud vergelyk, ten einde enige wanbalans vir
optimale groei vas te stel.
Dieselfde diere is in beide studies gebruik, naamlik ag springbokke, blesbokke en
rooibokke. 'n Beskrywing van die fisiese liggaamsamestelling het aangetoon dat die
uitslagpersentasies (% van liggaamsmassa; % van leë liggaamsmassa) van die drie
wildspesies as volg was: springbok (57.1 ± 2.4 %; 64.0 ± 2.5 %), blesbok (50.2 ± 2.1
%; 62.8 ± 1.4 %) en rooibok (57.4 ± 2.2 %; 65.6 ± 2.0 %). Die proporsionele
verspreiding van N in die karkas, uitwendige afval en inwendige afval is ook bepaal.
Die gemiddelde N konsentrasie in die karkas van die rooibok was hoër (P<0.05) as
die van die springbok en blesbok op 'n droë materiaal basis. Dit blyk vanaf die
chemiese samestelling van die karkas dat die drie wildspesies 'n groter potensiaal het
vir die produksie van maer vleis (vet-inhoud van karkas 4.7-5.2 %) as skape (17-25 %
vet). Manlike diere het 'n laer (P<0.05) vetpersentasie en 'n hoër (P<0.05)
vogpersentasie in beide die karkas en die drie-ribsnit teenoor die vroulike diere gehad.
'n Betekenisvolle korrelasie is tussen die persentasie vet in die drie-ribsnit en die
karkas van al drie wildspesies en vir beide geslagte gevind, op beide 'n nat en droë
materiaal basis. Die proteïeninhoud van dieselfde snitte was egter nie op 'n nat basis
betekenisvol gekorreleerd nie, en slegs die proteïen-inhoud van die springbok se drieribsnit
het verband gehou (P<0.05) met die in die karkas op 'n droë materiaal basis.
Die klem van die tweede studie was op die voedingsbehoeftes van springbok, blesbok
en rooibok, en meer spesifiek die essensiële aminosuurbenodighede. Daar is verskille
(P<0.05) tussen die totale leë liggaam essensiële aminosuursamestelling van die drie
wildspesies gevind. Hierdie verskille was aanwesig afgesien daarvan of die
hoeveelheid proteïen in berekening gebring is (g aminosure /100 g ruproteïen) of nie
(uitgedruk as % van lisien). Volgens die chemiese tellings was die vier mees
beperkende aminosure (drie vir rooibok) in die duodenale-inhoud vir totale leë
liggaamsgroei as volg: arginien, histidien, treonien en metionien (springbok);
metionien, arginien, histidien en lisien (blesbok); en metionien, histidien en arginien (rooibok). Verdere wanbalanse in die armnosure van die duodenale-inhoud was
aanwesig in die oormaat isoleusien (blesbok) en lisien, valien, leusien, treonien,
isoleusien en fenielalanien (rooibok). Die verhouding van die essensiële aminosure tot
lisien van die totale leë liggaam het by al drie wildspesies dieselfde tendens getoon.
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510 |
Mass spectrometric studies on protonated and alkali metal cationized amino acids and peptidesWong, Chiu-lan, Catherine., 黃超蘭. January 2003 (has links)
published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy
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