Bioacetoin Production by Bacillus subtilis subsp. subtilis Using Enzymatic Hydrolysate of Lignocellulosic Biomass
Date
2023-07
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Abstract
Abstract: Acetoin is an important bio-product useful in the chemical, food and pharmaceutical
industries. Microbial fermentation is the major process for the production of bioacetoin, as the
petroleum resources used in chemical methods are depleting day by day. Bioacetoin production
using wild microorganisms is an easy, eco-friendly and economical method for the production of
bioacetoin. In the present study, culture conditions and nutritional requirements were optimized
for bioacetoin production by a wild and non-pathogenic strain of B. subtilis subsp. subtilis JJBS250.
The bacterial culture produced maximum bioacetoin (259 mg L−1
) using peptone (3%) and sucrose
(2%) at 30 ◦C, 150 rpm and pH 7.0 after 24 h. Further supplementation of combinatorial nitrogen
sources, i.e., peptone (1%) and urea (0.5%), resulted in enhanced titre of bioacetoin (1017 mg L−1
)
by the bacterial culture. An approximately 46.22–fold improvement in bioacetoin production was
achieved after the optimization process. The analysis of samples using thin layer chromatography
confirmed the presence of bioacetoin in the culture filtrate. The enzymatic hydrolysate was obtained
by saccharification of pretreated rice straw and sugarcane bagasse using cellulase from Myceliophthora
thermophila. Fermentation of the enzymatic hydrolysate (3%) of pretreated rice straw and sugarcane
bagasse by the bacterial culture resulted in 210 and 473.17 mgL−1 bioacetoin, respectively. Enzy matic hydrolysates supplemented with peptone as a nitrogen source showed a two to four-fold
improvement in the production of bioacetoin. Results have demonstrated the utility of wild type B.
subtilis subsp. subtilis JJBS250 as a potential source for economical bioacetoin production by making
use of renewable and cost-effective lignocellulosic substrate. Therefore, this study will help in the
sustainable management of agricultural waste for the industrial production of bioacetoin, and in
combating environmental pollution.