The wood-feeding termite Coptotermes formosanus represents a unique and impressive system for lignocellulose degradation.The highly efficient digestion of lignocellulose is achieved through symbiosis with gut symbiont...The wood-feeding termite Coptotermes formosanus represents a unique and impressive system for lignocellulose degradation.The highly efficient digestion of lignocellulose is achieved through symbiosis with gut symbionts like bacteria.Despite extensive research during the last three decades,diversity of bacterial symbionts residing in individual gut regions of the termite and their associated functions is still lacking.To this end,cellulose,xylan,and dye-decolorization bacteria residing in foregut,midgut,and hindgut regions of C.formosanus were enlisted by using enrichment and culture-dependent molecular methods.A total of 87 bacterial strains were successfully isolated from different gut regions of C.formosanus which belonged to 27 different species of 10 genera,majorly affiliated with Proteobacteria(80%)and Firmicutes(18.3%).Among the gut regions,37.9%of the total bacterial isolates were observed in the hindgut that demonstrated predominance of cellulolytic bacteria(47.6%).The majority of the xylanolytic and dye-decolorization bacteria(50%)were obtained from the foregut and midgut,respectively.Actinobacteria represented by Dietza sp.was observed in the hindgut only.Based on species richness,the highest diversity was observed in midgut and hindgut regions each of which harbored seven unique bacterial species.The members of Enterobacter,Klebsiella,and Pseudomonas were common among the gut regions.The lignocellulolytic activities of the selected potential bacteria signpost their assistance to the host for lignocellulose digestion.The overall results indicate that C.formosanus harbors diverse communities of lignocellulolytic bacteria in different regions of the gut system.These observations will significantly advance our understanding of the termite–bacteria symbiosis and their microbial ecology uniquely existed in different gut regions of C.formosanus,which may further shed a light on its potential values at termite-modeled biotechnology.展开更多
In worldwide,the use of chemical pesticides to protect wood has been greatly restricted.In recent years,a large number of researchers devoted to the search for natural,safe and non-polluting bioactive chemical compoun...In worldwide,the use of chemical pesticides to protect wood has been greatly restricted.In recent years,a large number of researchers devoted to the search for natural,safe and non-polluting bioactive chemical compounds from plants as an alternative to synthetic organic chemical preservative.In Chinese folk,tung oil can be used as paint for wooden furniture to protect them from pests.This study aimed to evaluate the chemical compositions of raw and heated tung oil and their activity against termite.In choice bioassays,weight loss of wood treated with 5%raw or heated tung oil after 4 weeks was significantly less than that of the control group.In no-choice bioassays,there was a significant difference in termite survival and wood weight loss on raw and heated tung oil-treated wood.When tung oil-treatment concentrations increased to 5%,wood weight loss was less than 10%.There was no significant difference in termite survival and wood weight loss between raw and heated tung oil-treated wood.Survival of termites in both tung oil wood treatments was significantly lower than that in the starvation control after 4 weeks.Raw and heated tung oil significantly improved the resistance of pine wood to termites,and have the potential for the development of natural wood preservatives.展开更多
基金supported by the National Nat-ural Science Foundation of China(31900367,31772529)the National Key R&D Program of China(2018YFE0107100)+1 种基金Priority of Academic Program Development of Jiangsu Higher Education Institutions(PAPD 4013000011)supported in part by the Grant-in-Aid Startup Foundation(10JDG127)of Jiangsu University,China.
文摘The wood-feeding termite Coptotermes formosanus represents a unique and impressive system for lignocellulose degradation.The highly efficient digestion of lignocellulose is achieved through symbiosis with gut symbionts like bacteria.Despite extensive research during the last three decades,diversity of bacterial symbionts residing in individual gut regions of the termite and their associated functions is still lacking.To this end,cellulose,xylan,and dye-decolorization bacteria residing in foregut,midgut,and hindgut regions of C.formosanus were enlisted by using enrichment and culture-dependent molecular methods.A total of 87 bacterial strains were successfully isolated from different gut regions of C.formosanus which belonged to 27 different species of 10 genera,majorly affiliated with Proteobacteria(80%)and Firmicutes(18.3%).Among the gut regions,37.9%of the total bacterial isolates were observed in the hindgut that demonstrated predominance of cellulolytic bacteria(47.6%).The majority of the xylanolytic and dye-decolorization bacteria(50%)were obtained from the foregut and midgut,respectively.Actinobacteria represented by Dietza sp.was observed in the hindgut only.Based on species richness,the highest diversity was observed in midgut and hindgut regions each of which harbored seven unique bacterial species.The members of Enterobacter,Klebsiella,and Pseudomonas were common among the gut regions.The lignocellulolytic activities of the selected potential bacteria signpost their assistance to the host for lignocellulose digestion.The overall results indicate that C.formosanus harbors diverse communities of lignocellulolytic bacteria in different regions of the gut system.These observations will significantly advance our understanding of the termite–bacteria symbiosis and their microbial ecology uniquely existed in different gut regions of C.formosanus,which may further shed a light on its potential values at termite-modeled biotechnology.
基金This study was funded by College Students’Scientific Research Training Program of Zhejiang A&F University(No.113-2013200148)ZAFU-Institute of Termite Control of Yuhang cooperative project(2045200485,2045200529).
文摘In worldwide,the use of chemical pesticides to protect wood has been greatly restricted.In recent years,a large number of researchers devoted to the search for natural,safe and non-polluting bioactive chemical compounds from plants as an alternative to synthetic organic chemical preservative.In Chinese folk,tung oil can be used as paint for wooden furniture to protect them from pests.This study aimed to evaluate the chemical compositions of raw and heated tung oil and their activity against termite.In choice bioassays,weight loss of wood treated with 5%raw or heated tung oil after 4 weeks was significantly less than that of the control group.In no-choice bioassays,there was a significant difference in termite survival and wood weight loss on raw and heated tung oil-treated wood.When tung oil-treatment concentrations increased to 5%,wood weight loss was less than 10%.There was no significant difference in termite survival and wood weight loss between raw and heated tung oil-treated wood.Survival of termites in both tung oil wood treatments was significantly lower than that in the starvation control after 4 weeks.Raw and heated tung oil significantly improved the resistance of pine wood to termites,and have the potential for the development of natural wood preservatives.