Using mixed anaerobic communities to convert low value biomass into hydrogen

目前对微生物产氢的研究主要集中在纯培养和混合培养上。纯培养的研究使用无菌底物来防止污染。底物灭菌是使用纯培养物的主要缺点。能够利用非无菌原料的微生物培养可能更加灵活和具有成本效益。低价值的农业残留物，如玉米秸秆和小麦秸秆是非无菌原料的可能来源。含有酸化菌、产醋菌和产甲烷菌的混合培养基可以消耗来自低价值农业残留物的糖。然而，与持续产氢有关的一个主要问题是混合厌氧群落中耗氢生物的存在。本研究将着重于利用长链脂肪酸（LCFAs）抑制耗氢种群。本研究计划为研究和开发利用低价值农业废弃物厌氧制氢工艺提供了一个大纲。短期目标将确定影响氢气生产的环境和工艺参数。将进行批量研究，以检验几种长链脂肪酸（LCFAs）对戊糖和己糖发酵的影响。在批处理和连续流研究中，添加LCFAs将通过灭活非孢子形成的耗氢生物和选择更有利的产氢细菌来增加产氢量。长期目标的主要推动力将集中在开发一个可持续的连续系统来产生氢气。

Current research on microbial hydrogen production is focused on using pure and mixed cultures. Studies with pure cultures have utilized sterile substrates to prevent contamination. Substrate sterilization is a major disadvantage for processes using pure cultures. Microbial cultures which are able to utilize non-sterile feedstocks could be more flexible and cost effective. Low value agriculture residues such as corn stover and wheat stalks are possible sources of non-sterile feedstocks. Mixed cultures containing acidogens, acetogens and methanogens can consume sugars derived from low value agriculture residues. However, a major concern related to sustained hydrogen production is the presence of hydrogen consuming organisms in mixed anaerobic communities. The proposed research will focus on using long chain fatty acids (LCFAs) to inhibit the hydrogen consuming population. The research plan provides an outline for investigating and developing an anaerobic process for producing hydrogen using low value agriculture agriculture residues. The short-term objectives will identify environmental and process parameters affecting hydrogen production. Batch studies will be conducted to examine the effect of several long chain fatty acids (LCFAs) on the fermentation of pentose and hexose sugars. Adding LCFAs will be employed to increase hydrogen production by inactivating non-spore forming hydrogen consuming organisms and selecting the more favorable hydrogen producing bacteria in both batch and continuous flow studies. The major thrust of the long-term objectives will focus on developing a sustainable continuous system to generate hydrogen.