Inducible cellulase production from an organic solvent tolerant Bacillus sp. SV1 and evolutionary divergence of endoglucanase in different species of the genus Bacillus

Abstract

Bacteria are important sources of cellulases with various industrial and biotechnological applications. In view of this, a non-hemolytic bacterial strain, tolerant to various environmental pollutants (heavy metals and organic solvents), showing high cellulolytic index (7.89) was isolated from cattle shed soil and identified as Bacillus sp. SV1 (99.27% pairwise similarity with Bacillus korlensis). Extracellular cellulases showed the presence of endoglucanase, total cellulase and β-glucosidase activities. Cellulase production was induced in presence of cellulose (3.3 times CMCase, 2.9 times FPase and 2.1 times β-glucosidase), and enhanced (115.1% CMCase) by low-cost corn steep solids. An in silico investigation of endoglucanase (EC 3.2.1.4) protein sequences of three Bacillus spp. as query, revealed their similarities with members of nine bacterial phyla and to Eukaryota (represented by Arthropoda and Nematoda), and also highlighted of a convergent and divergent evolution from other enzymes of different substrate [(1,3)-linked beta-d-glucans, xylan and chitosan] specificities. Characteristic conserved signature indels were observed among members of Actinobacteria (7 aa insert) and Firmicutes (9 aa insert) that served as a potential tool in support of their relatedness in phylogenetic trees.

Construction of in situ degradation bacteria of corn straw and analysis of its degradation efficiency

“…It is a promising method to decompose it by cellulase produced by microorganisms (Sukumaran et al 2005;Octave and Thomas 2009). This enzyme is widely used in textile industry, pharmaceutical industry, food industry, biofuel, pollution control, and feed industry (Sreena et al 2016;Aarti et al 2018;Thomas et al 2018;Sreena and Sebastian 2018). Keeping crop straw in the field can supplement soil organic matter and improve soil fertility.…”

Identification and molecular characterization of a psychrophilic GH1 β-glucosidase from the subtropical soil microorganism Exiguobacterium sp. GXG2

“…Among these protein sequences, most of the β-glucosidases were came from bacteria (282,519) (Chan et al 2016; Chen et al 2017; Sun et al 2018), followed by fungi (11,863) (Guo et al 2015; Hernandez-Guzman et al 2016). The β-glucosidases have the characteristics of cold adaptation (Crespim et al 2016; Ueda et al 2010), heat resistance (Leis et al 2018), salt tolerance (Lee et al 2015), glucose tolerance (Chamoli et al 2016; Chan et al 2016), and organic solvent tolerance (Thomas et al 2018) in extreme environments. β-Glucosidase is an indispensable component in the process of cellulose conversion to glucose (Sorensen et al 2013).…”

Optimization of culture conditions for cellulase production in Acanthophysium Sp. KMF001 using response surface methodology

“…It has been reported that the MCC was the most effective carbon source for cellulase production by Trichoderma reesei strains (Dashtban et al 2011). Thomas et al (2018) also observed that the organism preferred to utilize MCC rather than CMC to produce cellulases. Jiménez-Leyva et al (2017) reported that the organisms showed good growth on either CMC or MCC, but their cellulase activities were better on MCC.…”

“…KMF001. In the literature, it has been reported that organic nitrogen sources such as yeast extract stimulated cell growth and cellulase production because yeast extract provides important growth factors such as carbon, sulfur, trace nutrient as well as nitrogenous compounds as complex hydrolysate obtained from yeasts (Thomas et al 2018). These researchers also mentioned that mixtures of the organic nitrogen sources such as tryptone or peptone caused low growth and cellulase production, and corn steep caused high cellulase production with maximum growth.…”