The enzymatic hydrolysis of cellulose has potential economical and environment-friendly applications. Therefore, discovery of new extremophilic cellulases is essential to meet the requirements of industry. Penicillium citrinum (MTCC 6489) that was previously isolated from soil in our laboratory, produced alkali tolerant and thermostable cellulases. Endoglucanase and filter paper activity hydrolase (FPAse) production of P. citrinum were studied using wheat bran substrate in solid state and submerged culture. Zymogram analysis of endoglucanase revealed the presence of two isoforms differing in molecular weight. One of them was 90 kDa and other one was 38 kDa. Partially purified endoglucanase showed two different peaks at pH 5.5 and 8.0, respectively, in its pH optima curve. But FPase showed only one peak (at pH 6.5) in its pH optima curve. Cellulase of P. citrinum is thermostable in nature. The present work reports for the first time, the alkali stable cellulase from alkali tolerant fungus Penicillium citrinum. Thermostable endoglucanase from P. citrinum may have potential effectiveness as additives to laundry detergents.

SANJAY GHOSH

Bio-Chemistry

T DUTTA

R SAHOO

R SENGUPTA

S S RAY

A BHATTACHARJEE

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Journal of Industrial Microbiology and Biotechnology

In this study, alkaliphilic family G/11 xylanase from alkali-tolerant filamentous fungi Penicillium citrinum MTCC 6489 was used as a model system to gain insight into the molecular aspects of unfolding/refolding of alkaliphilic glycosyl hydrolase protein family. The intrinsic protein fluorescence suggested a putative intermediate state of protein in presence of 2 M guanidium hydrochloride (GdmCl) with an emission maximum of 353 nm. Here we studied the refolding of GdmCl-denatured alkaline xylanase in the presence and the absence of a multimeric chaperone protein α-crystallin to elucidate the molecular mechanism of intramolecular interactions of the alkaliphilic xylanase protein that dictates its extremophilic character. Our results, based on intrinsic tryptophan fluorescence and hydrophobic fluorophore 8-anilino-1- naphthalene sulfonate-binding studies, suggest that α-crystallin formed a complex with a putative molten globule-like intermediate in the refolding pathway of xylanase in an ATP-independent manner. A 2 M GdmCl is sufficient to denature alkaline xylanase completely. The hydrodynamic radius (RH) of a native alkaline xylanase is 4.0, which becomes 5.0 in the presence of 2 M GdmCl whereas in presence of the higher concentration of GdmCl RH value was shifted to 100, indicating the aggregation of denatured xylanase. The α-crystallin•xylanase complex exhibited the recovery of functional activity with the extent of ∼43%. Addition of ATP to the complex did not show any significant effect on activity recovery of the denatured protein. © 2009 Humana Press.

Applied Biochemistry and Biotechnology

In vitro renaturation of alkaline family G/11 xylanase via a folding intermediate: Î±-Crystallin facilitates refolding in an ATP-independent manner

Aims: The enzymatic hydrolysis of xylan has potential economic and environment-friendly applications. Therefore, attention is focused here on the discovery of new extremophilic xylanase in order to meet the requirements of industry. Methods and Results: An extracellular xylanase was purified from the culture filtrate of P. citrinum grown on wheat bran bed in solid substrate fermentation. Single step purification was achieved using hydrophobic interaction chromatography. The purified enzyme showed a single band on SDS-PAGE with an apparent molecular weight of c. 25 kDa and pI of 3.6. Stimulation of the activity by β mercaptoethanol, dithiotheritol (DTT) and cysteine was observed. Moderately thermostable xylanase showed optimum activity at 50°C at pH 8.5. Conclusion: Xylanase purified from P. citrinum was alkaliphilic and moderately thermostable in nature. Significance and Impact of the Study: The present work reports for the first time the purification and characterization of a novel endoglucanase free alkaliphilic xylanase from the alkali tolerant fungus Penicillium citrinum. The alkaliphilicity and moderate thermostability of this xylanase may have potential implications in paper and pulp industries. © 2007 The Authors.

Letters in Applied Microbiology

A novel cellulase free alkaliphilic xylanase from alkali tolerant Penicillium citrinum: Production, purification and characterization

Cellulases from two Penicillium sp. strains isolated from subtropical forest soil: production and characterization

Journal of Applied Microbiology

Use of xylan-rich cost effective agro-residues in the production of xylanase by Streptomyces cyaneus SN32

Journal of Industrial Microbiology & Biotechnology

Xylanases of marine fungi of potential use for biobleaching of paper pulp

Bioresource Technology

High-yield cellulase production by Trichoderma reesei ZU-02 on corn cob residue

Novel cellulases from an extremophilic filamentous fungi Penicillium citrinum: production and characterization.

Journal	Journal of Industrial Microbiology and Biotechnology
Publisher	-
ISSN	1367-5435
Open Access	No