Origin,Selection And Succession Of Coastal Intertidal Zone-derived Bacterial Communities Associated With The Degradation Of Various Lignocellulose Substrates

Lignocellulose is the most abundant organic carbon polymer on the earth and microbial consortia were reported to play fundamental roles in the global carbon cycle and renewable energy production through the breakdown of complex organic carbon.It has been reported that the efficient lignocellulose degradation microbial community was selected from the terrestrial environment and microorganisms that can degrade lignocellulose have been enriched and screened in marine ecosystems.However,we have a poor understanding of how biotic/abiotic factors combine to influence consortia assembly and lignocellulose degradation.In this study,we used 96 in situ lignocellulose enriched,coastal intertidal zone-derived bacterial consortia as the initial inoculating consortia and developed 384 cultured consortia under different lignocellulose substrates(aspen,pine,rice straw,and purified Norway spruce lignin)with gradients of salinity and temperature.From the research,inoculum source,temperature,and salinity all determined the lignocellulose degradation,but dis played differential influences.Inoculum sources,including consortium diversity and composition,greatly impacted lignin degradation.In contrast,temperature was positively correlated with rice and pine lignocellulose degradation,while salinity negatively affected aspen lignocellulose degradation.The ability of the microbiota to grow and degrade individual lignocellulose was further assessed.All consortia showed similar rice straw consumption and growth rates,when they were cultured on that substrate.For the other three substrates(aspen,pine and purified Norway spruce lignin),the degradation values varied with the consortium tested,indicating a specificity for woody lignocellulose utilization.Taken together,as coastal consortia,salinity was the strongest driver for assembly,followed by Norway spruce lignin,temperature,and aspen.Moreover,a conceptual model was proposed to demonstrate different succession dynamics between consortia under herbaceous and woody lignocelluloses.The succession of consortium under Norway spruce lignin is greatly related with abiotic factors,while its substrate degradation is mostly correlated with biotic factors.A discrepant pattern was observed in the consortium under rice straw.Finally,we developed four groups of versatile,yet specific consortia.Our study not only reveals that coastal intertidal wetlands are important natural resources to enrich lignocellulolytic degrading consortia but also provides insights into the succession and ecological function of coastal consortium.The results of this study advanced our understanding of how the interaction of substrates.microbial inoculum,and culture conditions can influence consortium assembly and ecological function.