Structural and Biochemical Characterization of Endo-β-1,4-glucanase from Dictyoglomus thermophilum, a Hyperthermostable and Halotolerant Cellulase

Thermodynamics of a hyperthermostable carboxylesterase from Anoxybacillus geothermalis D9

Hyperthermostable enzymes are highly desirable biocatalysts due to their exceptional stability at extreme temperatures. Recently, a hyperthermostable carboxylesterase EstD9 from Anoxybacillus geothermalis D9 was biochemically characterized. The enzyme exhibited remarkable stability at high temperature. In this study, we attempted to probe the conformational adaptability of EstD9 under extreme conditions via in silico approaches. Circular dichroism revealed that EstD9 generated new β-sheets at 80 °C, making the core of the hydrolase fold more stable. Interestingly, the profiles of molecular dynamics simulation showed the lowest scores of radius of gyration and solvent accessible surface area (SASA) at 80 °C. Three loops were responsible for protecting the catalytic site, which resided at the interface between the large and cap domains. To further investigate the structural adaptation in extreme conditions, the intramolecular interactions of the native structure were investigated. EstD9 revealed 18 hydrogen bond networks, 7 salt bridges, and 9 hydrophobic clusters, which is higher than the previously reported thermostable Est30. Collectively, the analysis indicates that intramolecular interactions and structural dynamics play distinct roles in preserving the overall EstD9 structure at elevated temperatures. This work is relevant to both fundamental and applied research involving protein engineering of industrial thermostable enzymes.

Integrating multi-platform assembly to recover MAGs from hot spring biofilms: insights into microbial diversity, biofilm formation, and carbohydrate degradation

BACKGROUND

Hot spring biofilms provide a window into the survival strategies of microbial communities in extreme environments and offer potential for biotechnological applications. This study focused on green and brown biofilms thriving on submerged plant litter within the Sungai Klah hot spring in Malaysia, characterised by temperatures of 58-74 °C. Using Illumina shotgun metagenomics and Nanopore ligation sequencing, we investigated the microbial diversity and functional potential of metagenome-assembled genomes (MAGs) with specific focus on biofilm formation, heat stress response, and carbohydrate catabolism.

RESULTS

Leveraging the power of both Illumina short-reads and Nanopore long-reads, we employed an Illumina-Nanopore hybrid assembly approach to construct MAGs with enhanced quality. The dereplication process, facilitated by the dRep tool, validated the efficiency of the hybrid assembly, yielding MAGs that reflected the intricate microbial diversity of these extreme ecosystems. The comprehensive analysis of these MAGs uncovered intriguing insights into the survival strategies of thermophilic taxa in the hot spring biofilms. Moreover, we examined the plant litter degradation potential within the biofilms, shedding light on the participation of diverse microbial taxa in the breakdown of starch, cellulose, and hemicellulose. We highlight that Chloroflexota and Armatimonadota MAGs exhibited a wide array of glycosyl hydrolases targeting various carbohydrate substrates, underscoring their metabolic versatility in utilisation of carbohydrates at elevated temperatures.

CONCLUSIONS

This study advances understanding of microbial ecology on plant litter under elevated temperature by revealing the functional adaptation of MAGs from hot spring biofilms. In addition, our findings highlight potential for biotechnology application through identification of thermophilic lignocellulose-degrading enzymes. By demonstrating the efficiency of hybrid assembly utilising Illumina-Nanopore reads, we highlight the value of combining multiple sequencing methods for a more thorough exploration of complex microbial communities.

Microbial cellulase production and its potential application for textile industries

Purpose

The textile industry’s previous chemical use resulted in thousands of practical particulate emissions, such as machine component damage and drainage system blockage, both of which have practical implications. Enzyme-based textile processing is cost-effective, environmentally friendly, non-hazardous, and water-saving. The purpose of this review is to give evidence on the potential activity of microbial cellulase in the textile industry, which is mostly confined to the realm of research.

Methods

This review was progressive by considering peer-reviewed papers linked to microbial cellulase production, and its prospective application for textile industries was appraised and produced to develop this assessment. Articles were divided into two categories based on the results of trustworthy educational journals: methods used to produce the diversity of microorganisms through fermentation processes and such approaches used to produce the diversity of microbes through microbial fermentation. Submerged fermentation (SMF) and solid-state fermentation (SSF) techniques are currently being used to meet industrial demand for microbial cellulase production in the bio textile industry.

Results

Microbial cellulase is vital for increasing day to day due to its no side effect on the environment and human health becoming increasingly important. In conventional textile processing, the gray cloth was subjected to a series of chemical treatments that involved breaking the dye molecule’s amino group with Cl − , which started and accelerated dye(-resistant) bond cracking. A cellulase enzyme is primarily derived from a variety of microbial species found in various ecological settings as a biotextile/bio-based product technology for future needs in industrial applications.

Conclusion

Cellulase has been produced for its advantages in cellulose-based textiles, as well as for quality enhancement and fabric maintenance over traditional approaches. Cellulase’s role in the industry was microbial fermentation processes in textile processing which was chosen as an appropriate and environmentally sound solution for a long and healthy lifestyle.

A Novel Hyperthermostable Recombinant Protein Nanocage

Background

Background: Ferritin has an important role in iron storage in the cells, and due to its nanocage structure and self-assembly properties, it has wide application prospects in nanobiotechnology.

Methods

Methods: The maize (Zea mays) ferritin gene ZmFer1 was cloned and expressed in Escherichia coli BL21 (DE3) for the first time. Change in macromolecular structure of ZmFer1 ferritin due to heat treatment was investigated using native PAGE electrophoresis, dynamic light scattering (DLS), and transmission electron microscopy (TEM). Change in the secondary structures of the protein was evaluated using circular dichroism spectroscopy. Moreover, alteration in the conformation of the protein was evaluated using UV-absorption spectra and intrinsic fluorescence spectra. The melting temperature (Tm) of ZmFer1 was obtained using differential scanning calorimetry (DSC). Finally, the effect of heat on the function of ZmFer1 was assessed by iron loading ability.

Results

Results: The purified ZmFer1 protein showed a homopolymer nanocage structure. The results of native PAGE electrophoresis, DLS, and TEM techniques showed that ZmFer1 protein nanocage is stable to heat treatment up to 90 °C, and some of the protein nanocages retain their macromolecular structures even at 100 °C in liquid aqueous solution. Based on the DSC results, ZmFer1 protein nanocage had a Tm of 81.9 °C. After treatment at 100 °C, stable ZmFer1 protein nanocages were able to store iron atoms.

Conclusion

Conclusion: Recombinant ZmFer1 ferritin with a Tm > 80°C is a hyperthermostable protein nanocage. The results of this study are beneficial for the development of protein nanocages that are stable under extreme temperature conditions, as well as application of ZmFer1 in nanobiotechnology, biomaterials, and biomedical fields.