fungal bioremediation is a promising approach to remove heavy-metal from contaminated water. present study examined the ability of an earthworm gut fungus Trichoderma brevicompactum QYCD-6 to tolerate and remove both individual and multi-metals. the minimum inhibitory concentration (MIC) of heavy metals [Cu(II), Cr(VI), Cd(II) and Zn(II)] against the fungus was ranged 150-200 mg L −1 on composite medium, and MIC of Pb(II) was the highest with 1600 mg L −1 on potato dextrose (pD) medium. The Pb(II) presented the highest metal removal rate (97.5%) which mostly dependent on bioaccumulation with 80.0%, and synchronized with max biomass (6.13 g L −1) in PD medium. However, on the composite medium, the highest removal rate was observed for Cu(II) (64.5%). Cellular changes in fungus were reflected by TEM analysis. FTIR and solid-state NMR analyses indicated the involvement of different functional groups (amino, carbonyl, hydroxyl, et al.) in metallic biosorption. these results established that the earthworm-associated T. brevicompactum QYCD-6 was a promising fungus for the remediation of heavy-metal wastewater. Environmental pollution by heavy metals (such as Cr(VI), Cu(II), Cd(II), Pb(II) and Zn(II)), is widespread owing to urbanization, industrialization and agricultural practices 1,2. As multi-metals are non-biodegradable, they are constantly present in the environment and bio-accumulate in the tissues of plants, animals and humans, resulting in bio-magnification in the food chain. Biomagnified heavy metals lead to health disorders, such as osteomalacia, birth defects, and health hazards to the liver, kidneys, nervous and gastrointestinal systems 3,4. Toxic heavy metals are traditionally treated by physicochemical techniques, such as precipitation, membrane filtration, adsorption, and chemical oxidation-reduction 5. However, these methods are generally costly and ineffective when the metallic concentrations are low 1. The use of microorganisms to bioremediate is a cheaper and environmental friendly alternative approach to remove heavy metals from environment 6-8. Earthworms have the ability to accumulate heavy metals, including Cu, Cd, Pb and Zn 9. In general, metallic accumulation by earthworm occurs through two pathways, which include absorption following dermal contact and adsorption through the intestinal tissues 10-12. It has been reported that the gut microbiota of other animals were found to exhibit strong metals tolerance and binding abilities 13,14. So, it could be hypothesized that the intestinal microorganisms of earthworms have the ability of heavy metal tolerance and removal. In the course of our ongoing efforts to screen potential strain for metal removal from the gut microbiota of earthworm, we found that intestinal fungus Trichoderma brevicompactum QYCD-6 of Pheretima tschiliensis exhibited good potential for heavy metal tolerance. Here, we reported the details of the ability and mechanisms of tolerance and removal of the individual heavy metal as well as multiple metals by T. brevicompactum QYCD-6. T...

The phylogenetic diversity of fungi isolated from the Odontotermes formosanus was investigated by dilution-plate method, combined with morphological characteristics and 5.8S rDNA sequencing. Thirty-nine fungi were isolated and purified from O. formosanus, which were belonging to two phyla and four classes (Sordariomycetes, Dothideomycetes, Eurotiomycetes, Agaricomycetes). Furthermore, nine bacterial 16S rRNA sequences were obtained from total fungal genomic DNA. All bacterial symbionts were segmented into four genera: Bacillus, Methylobacterium, Paenibacillus, and Trabulsiella. The antimicrobial activities of all endophytic fungi extracts were tested by using the filter paper method against Escherichia coli (ATCC 8739), Bacillus subtilis (ATCC 6633), Staphylococcus aureus (ATCC 6538), and Canidia albicans (ATCC 10231). The results exhibited that 25 extracts (64%) exhibited antibacterial activity against at least one of the tested bacterial strains. Furthermore, the secondary metabolites 1 [5-hydroxyramulosin (1a):biatriosporin M (1b) = 2:1] from the Pleosporales sp. BYCDW4 exhibited potent antimicrobial activities against E. coli, C. albicans, B. subtilis, and S. aureus with the inhibition zone diameter (IZD) of 13.67, 14.33, 12.17, and 11.33 mm, respectively, which were comparable with those of the positive control. 1-(2,5-Dihydroxyphenyl)-3-hydroxybutan-1-one (2) from the Microdiplodia sp. BYCDW8 showed medium inhibitory activities against B. subtilis and S. aureus, with the IZD range of 8.32-9.13 mm. In conclusion, the study showed the diversity of insect symbionts could be expected to develop the resource of new species and antibiotics.

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43 Actinobacteria were isolated from the nest of Odontotermes formosanus. A phylogenetic analysis of 23 Actinobacteria isolates with different morphotypes showed that they did not form a monophyletic group. Antifungal bioassays exhibited that many strains inhibit both the termite cultivar Termitomyces and the competitor Xylaria. However, Actinobacteria inhibited the competitor Xylaria more severely than the termite cultural fungus Termitomyces. Furthermore, two Actinobacteria (Streptomyces sp. T33 and S. bellus T37) had a selective antifungal effect on Xylaria, with the inhibition zone of 25.5 and 8.9 mm, respectively. An actinomycin D was isolated from the strain T33 and had potent antifungal activity against Xylaria with IC 50 value of less than 3.1 µg/mL. In addition, further bioassays showed that actinomycin D possessed potent antifungal activities against Magnaporthe grisea (IC 50 = 0.9 µg/mL), Fusarium oxysporum f. sp. cucumerinum (IC 50 = 2.2 µg/mL), Valsa mali (IC 50 = 1.7 µg/mL), Rhizoctonia solani (IC 50 = 10.3 µg/mL), Dothiorella gregaria (IC 50 = 12.5 µg/mL) and F. oxysporum f. sp. mornordicae (IC 50 = 14.3 µg/mL), which were comparable to those of referenced cycloheximide. The findings of the present study suggest that the termite-associated Actinobacteria have a potential to be used as microbial fungicide.