Overexpression and characterization of alkaliphilic Bacillus firmus strain K-1 xylanase

Mongkorntanyatip, Karntichar; Limsakul, Puangpen; Khunrae, Pongsak

doi:10.1016/j.anres.2018.03.011

Cited by 4 publications

(1 citation statement)

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“…It is well known the existence of a synergistic relationship between cellulases and xylanases (Hu et al 2011; Kim et al 2014; Malgas et al 2017), that could be favoured by the pH conditions. Although xylanases from Bacillus and Paenibacillus have demonstrated to be active on a broad pH range (5 to 12) (Mongkorntanyatip et al 2017; Kurrataa’Yun and Meryandini 2015), the optimal pH interval for the majority of the bacterial endoglucanases is from 5 to 7 (Orencio-Trejo et al 2016; Sadhu and Maiti 2013). Under these physicochemical conditions, the removal of xylan by endo-xylanases, would allow the access of endo-cellulases to degrade cellulose microfibrils.…”

Section: Discussionmentioning

confidence: 99%

Degradation profile of nixtamalized maize pericarp by the action of the microbial consortium PM-06

et al. 2019

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The nixtamalized maize pericarp (NMP) is a plentiful by-product of the tortilla industry and an important source of fermentable sugars. The aim of this study was to describe the degradation profile of NMP by the action of a consortium (PM-06) obtained from the native microbial community of this residue. The degradation was analyzed in terms of the changes in the community dynamics, production of enzymes (endo-xylanase and endo-cellulase), physicochemical parameters, and substrate chemical and microstructural characteristics, to understand the mechanisms behind the process. The consortium PM-06 degraded 86.8 ± 3.3% of NMP after 192 h of growth. Scanning electron microscopy images, and the composition and weight of the residual solids, showed that degradation was sequential starting with the consumption of hemicellulose. Xylanase was the highest enzyme activity produced, with a maximum value of 12.45 ± 0.03 U mL −1 . There were fluctuations in the pH during the NMP degradation, starting with the acidification of the culture media and finishing with a pH close to 8.5. The most abundant species in the consortium, at the moment of maximum degradation activity, were Aneurinibacillus migulanus, Paenibacillus macerans, Bacillus coagulans, Microbacterium sp . LCT - H2 , and Bacillus thuringiensis. The diversity of PM-06 provided metabolic abilities that in combination helped to produce an efficient process. The consortium PM-06 generated a set of different tools that worked coordinated to increase the substrate availability through the solubilization of components and elimination of structural diffusion barriers. This is the first report about the degradation of NMP using a microbial consortium. Electronic supplementary material The online version of this article (10.1186/s13568-019-0812-7) contains supplementary material, which is available to authorized users.

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