A newly identified cellulase-producing Fusarium chlamydosporum HML278 was cultivated under solid-state fermentation of sugarcane bagasse, and two new β-glucosides enzymes (BG FH1, BG FH2) were recovered from fermentation solution by modified non-denaturing active gel electrophoresis and gel filtration chromatography. SDS-PAGE analysis showed that the molecular weight of BG FH1 and BG FH2 was 93 kDa and 52 kDa, respectively, and the enzyme activity was 5.6 U/mg and 11.5 U/mg, respectively. The optimal reaction temperature of the enzymes was 60 ℃, and the enzymes were stable with a temperature lower than 70 ℃. The optimal pH of the purified enzymes was 6.0, and the enzymes were stable between pH 4–10. Km and Vmax values ​​were 2.76 mg/mL and 20.6 U/mg for pNPG, respectively. Thin-layer chromatography and high-performance liquid chromatography analysis showed that BG FH1and BG FH2 had hydrolysis activity toward cellobiose and could hydrolyze cellobiose into glucose. In addition, both enzymes exhibited transglycoside activity, which could use glucose to synthesize cellobiose and cellotriose, and preferentially synthesize alcohol. In conclusion, our study demonstrated that F. chlamydosporum HML278 produces heat-resistant β-glucosidases with both hydrolytic activity and transglycosidic activity, and these β-glucosidases have potential application in bioethanol and papermaking industries.

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A newly screened cellulase-producing Fusarium chlamydosporum HML278 was cultivated under solid-state fermentation of sugarcane bagasse, and two new β-glucosides enzymes (BG FH1, BG FH2) from fermentation solution were recovered by modified non-denaturing active gel electrophoresis and gel filtration chromatography. SDS-PAGE analysis showed that the molecular weight of BG FH1and BG FH2 was 93 kDa and 52 kDa, respectively, and the enzyme activity was 5.6 U/mg and 11.5 U/mg, respectively. The optimal reaction temperature of the enzymes was 60 ℃, and the enzymes were stable under 70 ℃. The optimal pH of the purified enzymes was 6.0, and the enzymes were stable between pH 4–10. Km and Vmax values ​​of 2.76 mg/mL, 20.6 U/mg for pNPG. Thin-layer chromatography and high-performance liquid chromatography analysis showed that cellobiose BG FH1and BG FH2 had hydrolysis activity and can hydrolyze cellobiose into glucose. In addition, both enzymes also exhibited transglycoside activity, which can use low molecular weight monosaccharides to synthesize cellobiose and cellotriose, and preferentially synthesize alcohol. In conclusion, our study demonstrated that F. chlamydosporum HML278 can produce heat-resistant β-glucosidase with both hydrolytic activity and transglycosidic activity, and has potential application value in bioethanol and papermaking industries.

Although autochthonous bioaugmentation (ABA) has been applied to remove organic pollutants from wastewater, few studies have evaluated the roles of autochthonous microbes in eliminating polychlorinated biphenyls or polyaromatic hydrocarbons to reveal the mechanisms of ABA. Little research has been done to date to confirm the actual performance of introduced degraders in pollutant degradation in ABA and to explore a real-world scenario in which multiple pollutants coexist. Here, ABA by autochthonous strain Ralstonia sp. M1 was used to enhance the biodegradation of phenanthrene and biphenyl. The results showed a marked improvement in phenanthrene and biphenyl degradation in ABA, and the stable-isotope probing results first confirmed the direct involvement of Ralstonia sp. M1 in phenanthrene and biphenyl degradation. Additionally, ABA significantly altered the active degrading communities, and the abundance of the active degraders shared by both phenanthrene and biphenyl metabolisms was significantly improved in ABA, indicating their pivotal roles in improving phenanthrene and biphenyl degradation efficiency. Furthermore, ABA by strain Ralstonia sp. M1 promoted the interactions between the active degraders and other core microbes, consistent with the trends of pollutant removal. Collectively, our findings provide a better view of the mechanisms of ABA and offer new insights into the simultaneous degradation of multiple pollutants during ABA.