| dc.description.abstract | Nitriles are aliphatic and cyanide containing compounds R-CN. Nitriles are widespread in the
environment as a result of biological and industrial activities. Naturally occurring nitriles are
found in higher plants, bone oils, and insect. It been proven that microorganisms have the
capacity to synthesize naturally occurring nitriles. Synthetic nitriles, have been used in the
manufacture of herbicides such as 2,6-dichlorobenzonitrile and 3,5-dibromo-4hydroxybenzonitrile
and
the
synthesis
of
polymers,
plastics,
and
organic
solvents.
The
hydrolysis
of
nitrile involves two stepwise pathways with enzymes like nitrilases, amidases and nitrile
hydratase. Very little information is available on the ecological impact of organic nitriles and their
derivatives. It is highly conceivable that the direct discharge of wastewater containing some of
these nitrile compounds could cause severe health hazards, since most of them are highly toxic
and some are mutagenic and carcinogenic. Only a few microorganisms are able to metabolize
nitrile compounds and their derivatives. The aim of this research is to assess extremophiles
bacteria utilizing nitrile as the sole carbon and nitrogen by enzymatic reaction and to achieve this
aim there was different activities such as screening and exploring diversity of extremophile
bacteria from soil of soda lakes of Rift Valley on media enriched with butyronitrile and
isobutyronitrile and identification by morphology and biochemical test. The reason why soda
lake soils are used is because; a lot horticultural farming activities, is done around them so it is
assumed that these bacteria that degrade nitriles was present there also due to less competition
in extremophiles environment. Collected samples was serial diluted on 2.5ml isobutyronitrile and
2.5ml butyronitrile media both containing 2µl vitamin B 12 and 250ml lake water. Spread plating
and sub culturing was done on both media and incubated at 40°C for 7 days. Sixty pure isolates
were obtained, characterized morphologically and biochemically 30 isolate were gram positive
cocci.4 gram positive rod, one Gram negative and 25 were gram positive with spiral shape and
were classified as actinomycetes. Seven isolates utilized CMC, ten utilized cellulose, sixteen
utilized chitin, forty three utilized starch, nine utilized Xanthan, twenty three utilized skimmed
milk, three utilized lignin and twenty seven utilized tween 20. Most isolates were small white or
cream in color with regular shape but there were also yellow color with irregular shape or
filamentous. One isolate (BN02) utilized seven substrates. The aim of the study was achieved
because novel enzymes which can be used as biocatalytic were found. Lipases enzyme can be
produced to be used in the degradation of oil in water. | en_US |
