Aug 2026· International Journal of Biological Macromolecules· pp.
153852
· 0 citations· 73 references
Medicine
TL;DR
Overall, this study demonstrates the feasibility of producing a thermostable hemicellulolytic secretome from low-cost agro-industrial residues and identifies Parageobacillus sp.
Abstract
The development of robust enzyme systems and the use of low-cost feedstocks for lignocellulosic biomass deconstruction remain major challenges for biorefineries. Here, we report a strategy to discover and produce thermostable hemicellulolytic enzymes from industrial microbiomes enriched on spent mushroom substrate (SMS) at 70 °C. A thermophilic bacterium representing a putative novel species, Parageobacillus sp. DSM 35475, was isolated and cultivated on a medium composed exclusively of SMS and digestate, demonstrating the feasibility of producing extracellular enzymes from agro-industrial residues. The resulting cell-free secretome exhibited xylanase activity of 0.22 U/mL, with an optimum at 80 °C and pH 7, while retaining more than 30% of its maximal activity between 60 and 90 °C and more than 50% activity after prolonged incubation at 75-80 °C. More than 40% of the initial activity was preserved after 80 days of storage at 4 °C. HPAEC-PAD analysis of hydrolysis products, together with zymographic and genomic analyses, indicated the presence of a multifunctional hemicellulolytic system comprising endo-xylanase, β-xylosidase, α-L-arabinofuranosidase, and endo-mannanase activities. The secretome hydrolysed beechwood xylan, arabinoxylan and alkali-pretreated SMS, releasing mixtures of mono- and oligosaccharides under thermophilic conditions. Genome annotation predicted a diverse CAZyme repertoire and a dedicated xylan/arabinan utilisation locus consistent with the observed biochemical phenotype. Overall, this study demonstrates the feasibility of producing a thermostable hemicellulolytic secretome from low-cost agro-industrial residues and identifies Parageobacillus sp. DSM 35475 as a promising source of thermophilic enzymes for future lignocellulose bioconversion.
BSEG2 is highly thermostable, tolerant of high salt and ionic liquids, and notably resistant to cellobiose inhibition up to 200 mM, suggesting potential to reduce freshwater demand in biomass processing and a strong candidate for simplified, cost-effective enzyme formulations for glucose production from lignocellulosic feedstocks.
Debjyoti Ghosh, Aditi Konar, Yi Gao et al.· Biotechnology Journal· 0 citations
Local enrichment of acidic residues on the PlGH3 surface could generate a negative electrostatic potential, which enables adaptation to high-salt and alkaline environments, thereby sustaining the enzyme's catalytic activity under such extreme conditions.
Kaijuan Wu, Ke Guo, Zheng Yu et al.· Applied Biochemistry and Bio...· 0 citations
Among the 20 isolates, one isolate was identified as Brevibacillus parabrevis PS12, representing the first report from Iraqi soil, which contributed to an increase in bacterial biomass which led to a rise in the specific activity of arginase.
Ayah Muwafaq Hussein, Aqeel Mohammed Majeed Al-Ezee, Zaid Raad Abbas· Journal of the College of B...· 0 citations
Lipases obtained from thermophilic microorganisms are attracting great interest in the industrial field due to their stability under high-temperature conditions and their wide range of industrial applications. In this study, thermophilic bacterial strains were isolated from water and mud samples collected from Erzurum Ilica Hot Springs (Turkey). An isolate producing a potent extracellular lipase was selected, named IO3, and identified by 16S rRNA sequencing. Sequencing analysis revealed that this isolate showed 99% similarity to Aeribacillus pallidus. The lipase enzyme purified from the isolate was obtained using two comparative strategies. The conventional multi-stage chromatographic approach, which includes ammonium sulfate precipitation, ion exchange chromatography, and gel filtration chromatography, provided 9.3-fold purification with a 3.18% recovery. However, the alternative Three-Phase Partitioning (TPP) system provided rapid, single-step recovery with a significantly higher yield of 38.79%, although the purification fold remained 0.65 under the tested conditions. The molecular weight of the purified A. pallidus IO3 lipase was determined to be approximately 33.88 kDa by SDS-PAGE. The enzyme showed optimum activity at pH 8.0 and 50 °C and maintained considerable thermal stability; the enzyme retained significant activity levels (45-69%) even at high temperatures such as 70 °C and 80 °C after an incubation period of 120 minutes. Among the tested metal ions, Fe2+, Fe³+, Cu2+, and Zn2+ enhanced enzyme activity, while the enzyme showed stability in the presence of Li+ and Cu2+ ions. Lipase activity also increased in the presence of surfactants, while chloroform enhanced enzyme activity by 22-338% depending on solvent concentration. The enzyme showed the highest activity toward p-nitrophenyl palmitate. The enzyme was completely inhibited by DTNB, IAA, and EDTA. In addition, the enzyme retained low activity in the presence of β-mercaptoethanol. The Km and Vmax values were calculated as 0.46 mM and 51.44 µmol·min-1·mg-1, respectively, using nonlinear regression analysis. Overall, these findings indicate that A. pallidus IO3 lipase is a thermostable and chemically tolerant enzyme with potential applicability in industrial biocatalysis and detergent-related processes.
Ikra Ozkan, A. Adiguzel· Preparative Biochemistry & B...· 0 citations
The study re-analyzed the draft genome of Bacillus licheniformis SMIA-2 and generated a reference-guided pseudo-scaffold. Cross-validated genome annotation identified five candidate loci associated with pectin degradation, including putative pectate lyases, polygalacturonase, and downstream uronate-catabolic genes. Submerged fermentation with passion fruit peel flour and corn steep liquor yielded crude enzymatic extracts, which were spray-dried at 110 °C using maltodextrin and microcrystalline cellulose as stabilizers. The dried formulation retained pectinase activity for 180 days at 5 °C and showed additional cellulase, amylase, xylanase, and protease activities. Pectinase displayed optimal activity at pH 8.5 and 70 °C, with stability between pH 8.0–8.5 and 65–70 °C. Despite not using a reference strain and the absence of some omics analyses, with genomic and industrial claims presented as evidence of biotechnological potential rather than definitive functional validation of individual genes, these results support a sustainable, scalable, and alkaline-tolerant enzyme platform based on agro-industrial residues.
E. Cruz, Larissa Pacheco Ferreira, A. Rosana et al.· Food Science and Biotechnolo...· 0 citations
