Species of the genus Chryseobacterium (family Flavobacteriaceae) occur widely
in clinical, environmental and industrial ecosystems. In the clinical environment,
they are uncommon etiologic agents, but their infections may be serious in
immunocompromised patients. They are often resistant to multiple antimicrobial
agents making infections due to these organisms potentially difficult to treat. In
the food environment, they are known to cause spoilage of foods such as canned
products, milk and dairy products, fish, meat and poultry.
It is therefore necessary to be able to solve or anticipate and avert possible
problems caused by Chryseobacterium species. This genus also has positive
characteristics which include synthesis of a number of enzymes potentially useful
in industry (e.g. keratinolytic enzymes), medicine (e.g. prion degradation) and
turnover of organic matter in soil, water and sewage plants. Taxonomic studies
are key to solving such problems by characterization and identification of such
organisms. This also sets the foundation for investigation of the organismâs
beneficial roles and applications.
In this study, some Chryseobacterium strains isolated from poultry feather waste
and raw chicken, were phenotypically characterized and identified using
conventional tests and the BIOLOG Omnilog Gen II system. Phylogenies of
seven selected isolates were determined using the 16S rRNA gene sequence
analysis and they were further characterized using the BIOLOG Omnilog Gen III
identification system. They fell into four taxonomic groups (Group 1: 1_F178;
Group 2: 5_R23647; Group 3: 6_F141B and 7_F195; and Group 4: 8_R23573,
9_R23581 and 10_R23577) which did not show affiliation to any currently
recognised type species of the genus Chryseobacterium suggesting that these
groups were possible representatives of novel species. Three selected strains (8_R23573, 9_R23581 and 10_R23577) were subjected to
a polyphasic taxonomic study to determine their exact taxonomic identities.
Results of the predominant respiratory menaquinone, fatty acid methyl esters and
DNA base composition supported the affiliation of the strains to the genus
Chryseobacterium. When subjected to DNA-DNA hybridization, the strains gave
relatedness values of more than 81% among the three strains and less than 57%
similarity between the strains and their two nearest phylogenetic neighbours C.
shigense (DSM 17126T) and C. luteum (LMG23785T). A novel species emerged
after a comparison of the phenotypic, chemotypic and genotypic results. The new
species was described and the name Chryseobacterium carnipullorum sp. nov.
was proposed.
Analysis using the BIOLOG Phenotype MicroArray (PM) system, revealed that C.
carnipullorum has the potential to cause food spoilage mainly by utilizing
carbohydrates, carboxylic acids and amino acids by producing metabolites which
lead to souring, butyric spoilage defects, alkalinisation, bitter tastes and sulphide
spoilage. The organism was also shown to have potential for biotechnological
applications in food and stockfeed technology; coffee extraction, oil drilling and
detergent industries; manufacture of artificial antigens and chemical diagnostic
agents and release of oligosaccharides and oligopeptides in (ultra) oligotrophic
freshwater environments.
It was found that the new species was able to produce extracellular keratinases
that were able to extensively degrade chicken feather waste in 48 h. This has the
potential of contributing toward solving the disposal problem which is experienced
by the poultry industry that produces huge amounts of the recalcitrant feather
waste as a by-product. Currently, a very small percentage of feather waste is
steamed, treated chemically and ground to form dietary protein supplement for
stockfeeds. Degradation of feathers using keratinolytic organisms is a more
economical and environmentally friendly alternative. Chryseobacterium
carnipullorum also has the potential for application in other biotechnological
processes involving keratin hydrolysis. Hydrolysed feathers can be converted to
fertilizers, glues, films, and they can be used as the source of rare amino acids,
such as serine, cysteine and proline.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ufs/oai:etd.uovs.ac.za:etd-05272013-110516 |
| Date | 27 May 2013 |
| Creators | Charimba, George |
| Contributors | Prof PJ Jooste, Prof CJ Hugo |
| Publisher | University of the Free State |
| Source Sets | South African National ETD Portal |
| Language | en-uk |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.uovs.ac.za//theses/available/etd-05272013-110516/restricted/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University Free State or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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