Jatropha curcas seed cake as substrate for production of xylanase and cellulase by Aspergillus niger FGSCA733 in solid-state fermentation
메타 데이터
바이오화학분류
바이오플라스틱
기타
바이오정밀화학
연료
기타
논문
Jatropha curcas seed cake as substrate for production of xylanase and cellulase by Aspergillus niger FGSCA733 in solid-state fermentation
학술지
Industrial crops and products
저자명
Ncube, Thembekile; Howard, Rachmond L.; Abotsi, Emil K.; van Rensburg, Elbert L. Jansen; Ncube, Ignatious
초록
<P><B>Highlights</B></P><P>► The increased demand for renewable sources of fuels has made <I>Jatropha curcas</I> a non-food crop an important crop in the production of biodiesel due to the high oil content of the <I>Jatropha</I> seed. ► Utilisation of the seed cake would add value and economical viability of <I>Jatropha</I> as an oil crop. The utilisation of the seed cake as animal feed is still very limited due to toxicity from a range of antinutritional factors. Detoxification of the seed cake so far has not been viable. ► The results presented in our manuscript demonstrate the potential of the seedcake as substrate in producing high levels of xylanase and cellulase. ► Our findings provide a route to adding value to the <I>Jatropha</I> crop and reducing the cost of industrial enzyme production. The paper generates interest in the use of <I>Jatropha</I> cake in the production of lignocellulolytic enzymes through solid state fermentation. Hence the results presented in this manuscript contribute new knowledge towards the alternative use of <I>Jatropha</I> seed cake as a cheap substrate in fermentation processes for production of industrial enzymes.</P> <P><B>Abstract</B></P><P><I>Jatropha curcas</I> seed-cake was evaluated for use as a solid state fermentation substrate for production of cellulolytic and xylanolytic enzymes by <I>Aspergillus niger.</I> Supplementation of the seedcake with 10% thatch grass (<I>Hyperrhaenia</I> sp.) resulted in a fivefold increase in xylanase production. Ammonium chloride supplementation increased production of xylanase by 13%. Under the same conditions, cellulase production was not influenced by supplementation with grass or the nitrogen sources used. Maximum xylanase was produced at 25°C whilst cellulase was maximally produced at 40°C. Highest xylanase activity was obtained when the cultures had an initial pH of 3 whereas cellulase was maximally produced at an initial pH of 5. Under optimised conditions, 6087U and 3974U of xylanase and cellulase respectively were obtained per gram of substrate. Zymograms of crude enzyme extracts showed six active bands ranging from 20kDa to 43kDa for cellulase and a 31kDa active band for xylanase.</P>