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Adaptive Enrichment of a Thermophilic Bacterial Isolate for Enhanced Enzymatic Activity

The mimicking of evolution on a laboratory timescale to enhance biocatalyst specificity, substrate utilization activity, and/or product formation, is an effective and well-established approach that does not involve genetic engineering or regulatory details of the microorganism. The present work empl...

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Autores principales: Govil, Tanvi, Saxena, Priya, Samanta, Dipayan, Singh, Sindhu Suresh, Kumar, Sudhir, Salem, David R., Sani, Rajesh K.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7355623/
https://www.ncbi.nlm.nih.gov/pubmed/32526936
http://dx.doi.org/10.3390/microorganisms8060871
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author Govil, Tanvi
Saxena, Priya
Samanta, Dipayan
Singh, Sindhu Suresh
Kumar, Sudhir
Salem, David R.
Sani, Rajesh K.
author_facet Govil, Tanvi
Saxena, Priya
Samanta, Dipayan
Singh, Sindhu Suresh
Kumar, Sudhir
Salem, David R.
Sani, Rajesh K.
author_sort Govil, Tanvi
collection PubMed
description The mimicking of evolution on a laboratory timescale to enhance biocatalyst specificity, substrate utilization activity, and/or product formation, is an effective and well-established approach that does not involve genetic engineering or regulatory details of the microorganism. The present work employed an evolutionary adaptive approach to improve the lignocellulose deconstruction capabilities of the strain by inducing the expression of laccase, a multicopper oxidase, in Geobacillus sp. strain WSUCF1. This bacterium is highly efficient in depolymerizing unprocessed lignocellulose, needing no preprocessing/pretreatment of the biomasses. However, it natively produces low levels of laccase. After 15 rounds of serially adapting this thermophilic strain in the presence of unprocessed corn stover as the selective pressure, we recorded a 20-fold increase in catalytic laccase activity, at 9.23 ± 0.6 U/mL, in an adapted yet stable strain of Geobacillus sp. WSUCF1, compared with the initial laccase production (0.46 ± 0.04 U/mL) obtained with the unadapted strain grown on unprocessed corn stover before optimization. Chemical composition analysis demonstrated that lignin removal by the adapted strain was 22 wt.% compared with 6 wt.% removal by the unadapted strain. These results signify a favorable prospect for fast, cost competitive bulk production of this thermostable enzyme. Also, this work has practical importance, as this fast adaptation of the Geobacillus sp. strain WSUCF1 suggests the possibility of growing industrial quantities of Geobacillus sp. strain WSUCF1 cells as biocatalysts on reasonably inexpensive carbon sources for commercial use. This work is the first application of the adaptive laboratory evolution approach for developing the desired phenotype of enhanced ligninolytic capability in any microbial strain.
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spelling pubmed-73556232020-07-23 Adaptive Enrichment of a Thermophilic Bacterial Isolate for Enhanced Enzymatic Activity Govil, Tanvi Saxena, Priya Samanta, Dipayan Singh, Sindhu Suresh Kumar, Sudhir Salem, David R. Sani, Rajesh K. Microorganisms Article The mimicking of evolution on a laboratory timescale to enhance biocatalyst specificity, substrate utilization activity, and/or product formation, is an effective and well-established approach that does not involve genetic engineering or regulatory details of the microorganism. The present work employed an evolutionary adaptive approach to improve the lignocellulose deconstruction capabilities of the strain by inducing the expression of laccase, a multicopper oxidase, in Geobacillus sp. strain WSUCF1. This bacterium is highly efficient in depolymerizing unprocessed lignocellulose, needing no preprocessing/pretreatment of the biomasses. However, it natively produces low levels of laccase. After 15 rounds of serially adapting this thermophilic strain in the presence of unprocessed corn stover as the selective pressure, we recorded a 20-fold increase in catalytic laccase activity, at 9.23 ± 0.6 U/mL, in an adapted yet stable strain of Geobacillus sp. WSUCF1, compared with the initial laccase production (0.46 ± 0.04 U/mL) obtained with the unadapted strain grown on unprocessed corn stover before optimization. Chemical composition analysis demonstrated that lignin removal by the adapted strain was 22 wt.% compared with 6 wt.% removal by the unadapted strain. These results signify a favorable prospect for fast, cost competitive bulk production of this thermostable enzyme. Also, this work has practical importance, as this fast adaptation of the Geobacillus sp. strain WSUCF1 suggests the possibility of growing industrial quantities of Geobacillus sp. strain WSUCF1 cells as biocatalysts on reasonably inexpensive carbon sources for commercial use. This work is the first application of the adaptive laboratory evolution approach for developing the desired phenotype of enhanced ligninolytic capability in any microbial strain. MDPI 2020-06-09 /pmc/articles/PMC7355623/ /pubmed/32526936 http://dx.doi.org/10.3390/microorganisms8060871 Text en © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Govil, Tanvi
Saxena, Priya
Samanta, Dipayan
Singh, Sindhu Suresh
Kumar, Sudhir
Salem, David R.
Sani, Rajesh K.
Adaptive Enrichment of a Thermophilic Bacterial Isolate for Enhanced Enzymatic Activity
title Adaptive Enrichment of a Thermophilic Bacterial Isolate for Enhanced Enzymatic Activity
title_full Adaptive Enrichment of a Thermophilic Bacterial Isolate for Enhanced Enzymatic Activity
title_fullStr Adaptive Enrichment of a Thermophilic Bacterial Isolate for Enhanced Enzymatic Activity
title_full_unstemmed Adaptive Enrichment of a Thermophilic Bacterial Isolate for Enhanced Enzymatic Activity
title_short Adaptive Enrichment of a Thermophilic Bacterial Isolate for Enhanced Enzymatic Activity
title_sort adaptive enrichment of a thermophilic bacterial isolate for enhanced enzymatic activity
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7355623/
https://www.ncbi.nlm.nih.gov/pubmed/32526936
http://dx.doi.org/10.3390/microorganisms8060871
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