Thesis (MSc)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: Bontebok, Damaliscus pygargus pygargus, formerly classified as D. dorcas
dorcas, are territorial animals with interdigital glands between the toes of the
forelegs. Males regularly defecate on dung heaps, on which they often lie, to
communicate with other members of their species. They also communicate by
means of visual displays, scent marking and occasionally with scraping or
pawing of dung heaps. It is assumed that scent marking with the interdigital
secretion serves to define territories frequented by these antelope. These
glands secrete a complex mixture of volatile and non-volatile compounds and
the volatile compounds in the secretion serve as a chemical signal for other
bontebok.
It has been suggested that the interdigital secretion is not produced in its final
composition by the interdigital gland alone, but that microbial activity is
responsible for many of the compounds present in the secretion. In general,
many compounds can be attributed to the by-products of microbial hydrolysis
of triglycerides, a common characteristic of sebum. It is well documented that
micro-organisms inhabit the deep recesses of sebaceous glands and the
presence of micro-organisms has been found to be consistent in all antelope
exocrine glandular areas.
This study involved the chemical characterisation of the volatile metabolites
produced in vitro by micro-organisms from the interdigital cavity of the
bontebok.
Various comparative studies were made, one of which was comparison of the
metabolites produced by the individual microbial species as well as the total
community of bacteria incubated in different media. A comparison of the compounds identified in the interdigital secretion and the metabolites produced
by the micro-organisms in the different media was also made.
The volatile metabolite extracts of the individual bacterial species and of the
total community were chemically characterised by low-resolution gas
chromatography-mass spectroscopy. Classes of compounds identified from
the volatile metabolite extracts include:
• Acids - Aliphatic (saturated and unsaturated)
• Alcohols - Aliphatic (saturated and unsaturated)
• Aldehydes - Aliphatic (saturated and unsaturated)
• Aromatic compounds
• Ketones - Aliphatic (saturated and unsaturated)
• Pyrazines
• Dimethyldisulphide
• Squalene and cholesterol
Several qualitative differences were found between the compounds identified in
the volatile metabolite extracts of the micro-organisms when incubated in
tryptic soy broth (TSB) and minimal salt medium (MSM). In particular, when the
microbes were incubated in TSB medium a number of pyrazines were found
that were not present when utilising MSM as a medium.
Additional qualitative differences were found between the compounds identified
in the metabolite extracts of the individual bacterial species and the total
community of bacteria, when incubated in both TSB and MSM media.
A comparison of the interdigital secretion and the metabolite extracts of the
microbial communities incubated in TSB and MSM revealed that many compounds produced in MSM corresponded to the compounds identified in the
interdigital secretion. These corresponding compounds were found to be
saturated and unsaturated acids, aldehydes and squalene. Furthermore, there
was only one corresponding compound in the case of TSB as medium. / AFRIKAANSE OPSOMMING: Die bontebok, Damaliscus pygargus pygargus, voorheen geklassifiseer as D.
dorcas dorcas, is 'n territoriale dier met interdigitale kliere tussen die kloutjies
van die voorpote. Ramme ontlas gereeld op mishope, waarop hulle dikwels lê,
om met ander lede van die spesie te kommunikeer. Hulle kommunikeer ook
deur middel van visuele seine, reukmerking en soms deur mishope met die
voorpote te kap of te skraap. Reukmerking met die interdigitale afskeiding dien
klaarblyklik om gebiede wat deur hierdie diere bewoon word, af te baken. Die
interdigitale kliere skei 'n komplekse mengsel van vlugtige en nie-vlugtige
verbindings af en die vlugtige verbindings dien as chemiese sein vir ander
bontebokke.
Die vermoede bestaan dat die interdigitale klier nie alleen verantwoordelik is vir
die finale samestelling van die interdigitale afskeiding nie, maar dat
mikrobiese aktiwiteit bydra tot die produksie van baie van die verbindings wat
in die afskeiding aanwesig is. Sekere verbindings kan in die algemeen
toegeskryf word aan die vorming van die neweprodukte van mikrobiese
hidrolise van trigliseriede, 'n algemene eienskap van sebum. Dit is bekend dat
die diep holtes van vetkliere 'n goeie teelaarde is vir mikroorganismes en daar
is gevind dat mikroorganismes feitlik deurgaans voorkom in alle anteloop
eksokriene klierareas.
Hierdie studie behels die chemiese karakterisering van die vlugtige metaboliete
wat in vitro deur mikroorganismes van die interdigitale klierholte van die
bontebok geproduseer word.
Verskeie vergelykende studies is uitgevoer waarvan een die vergelyking was
van die metaboliete wat deur die individuele mikrobiese spesies sowel as die totale gemeenskap van bakterieë geproduseer word tydens inkubasie in
verskillende media. Vergelyking van die verbindings wat in die interdigitale
afskeiding geïdentifiseer is met die metaboliete wat in verskillende media
geproduseer is, het ook deel van die studie uitgemaak.
Die vlugtige metaboliet ekstrakte van die individuele bakteriese spesies en van
die totale gemeenskap is chemies gekarakteriseer deur middel van laeresolusie
gaschromatografie-massaspektrometrie. Die volgende groepe
verbindings is onder andere in die vlugtige metaboliet ekstrakte geïdentifiseer:
• Sure - Alifaties (versadig en onversadig)
• Alkohole - Alifaties (versadig en onversadig)
• Aldehiede - Alifaties (versadig en onversadig)
• Aromatiese verbindings
• Ketone - Alifaties (versadig en onversadig)
• Pirasiene
• Dimetieldisulfied
• Skwaleen en cholesterol
Verskeie kwalitatiewe verskille is gevind tussen die verbindings wat
geïdentifiseer is in die vlugtige metaboliet ekstrakte van die mikroorganismes
onderskeidelik in TSB medium en MSM geïnkubeer. Opvallend was
byvoorbeeld die voorkoms van pirasiene in gevalle waar mikroorganismes in
TSB medium geïnkubeer is, terwyl hierdie groep verbindings afwesig was
wanneer MSM gebruik is.
Onderlinge kwalitatiewe verskille is ook gevind tussen die verbindings wat
geïdentifiseer is in die metaboliet ekstrakte van die individuele bakteriese spesies en die totale gemeenskap van bakterieë, wanneer in TSB medium
sowel as in MSM geïnkubeer is.
Vergelyking van die verbindings in die interdigitale afskeiding en in die
metaboliet ekstrakte van die mikrobiese gemeenskappe, het getoon dat 'n
aantal verbindings wat in MSM geproduseer is, ooreenstem met verbindings
wat in die interdigitale afskeiding geïdentifiseer is. Daar is gevind dat hierdie
verbindings versadigde en onversadigde sure en aldehiede en skwaleen is.
Met TSB as medium was daar slegs een ooreenstemmende verbinding.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/53774 |
| Date | 03 1900 |
| Creators | Scott, Gary Terri |
| Contributors | Le Roux, M., Burger, B. V., Stellenbosch University. Faculty of Science. Dept. of Chemistry & Polymer Science. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | Unknown |
| Type | Thesis |
| Format | 166 p. : ill. |
| Rights | Stellenbosch University |
Page generated in 0.0031 seconds