The Role of Lactic Acid Bacteria and its Application to Fermentation Processes by Ecosystem Engineering Approach.

在食品发酵和酿造过程中，可以观察到两种以上的微生物相互作用，这一过程被称为混合培养系统。在发酵过程中产生的食品和饮料的味道和风味与这些微生物的协同作用密切相关。本研究项目旨在分析威士忌酿造过程中酵母与乳酸菌的协同作用，并分析和控制乳酸菌与丙酸菌混合培养系统中一种自生菌nisin a的产生。在威士忌酿造过程中，提出了用流式细胞术测定细胞浓度的方法。利用流式细胞仪，采用PI和FITC标记技术，可以准确区分酵母和乳酸菌的各细胞浓度并进行定量测定。此外，还分析了酵母和乳酸菌对发酵过程中多糖含量的影响。据报道，酵母不能同化某些种类的麦芽寡糖，而乳酸菌可以同化。因此，在本研究中，我们研究了酵母和乳酸菌对麦芽寡糖的同化能力。本研究使用的乳酸菌不能吸收酵母不能吸收的一些麦芽寡糖。这一结果表明，糖的同化能力强烈依赖于菌株。研究了乳酸菌生产天然食品保鲜添加剂乳酸链球菌素a的工艺。为避免在培养基中添加酸和碱进行pH调节，对产nisin A乳酸菌和丙酸菌进行了混合培养。在混合培养体系中，乳酸菌产生的乳酸被丙酸菌吸收。最后，与不加pH控制的乳酸菌纯培养相比，混合培养的乳酸链球菌素A的产量提高了2倍。少

In food fermentation and brewing processes, more than two species of microorganisms can be observed interacting with each other and the process is called as a mixed culture system. The tastes and flavors in foods and drinks made in fermentation processes are strongly correlated with the synergic interaction of these microorganisms. The aims of this research project are to analyze the synergic interaction of yeasts and lactic acid bacteria in whisky brewing process and to analyze and to control the production of a kind of autibiotics, nisin A,in a mixed culture system of lacti acid bacteria and propionic acid bacteria.In whisky brewing process, the measurement method of the cell concentration by a flowcytometry was developed. Each cell concentrations of yeast and lactic acid bacterium could be accurately distinguished and measured quantitatively by PI and FITC labelling techniques, using the flowcytometer. Moreover, the role of yeast and lactic acid bacteria for, concerning with assimil … More ation of polysaccharide was analyzed. It has been reported that yeasts cannot assimilate some kinds of malto-oligosaccharides but lactic acid becteria can assimilate them. Thus, in this study, we investigated the ability for assimilation of malto-oligosaccharides by yeast and lactic acid bacteria. The lactic acid bacteria using in this study could not assimilate some kinds of malto-oligosaccharides, which could not be assimilated by yeasts. This result suggested the ability for the assimilation of the saccharides was strongly dependent on the strain.The production of a kind of natural food preservation additives, antibiotic nisin A,by lactic acid bacterium was investigated. In order to avoid the addition of acid and alkaline for pH adjust, the mixed culture of nisin A producing lactic acid bacterium and propionic acid bacterium was performed. In the mixed culture system, the lactic acid produced by lactic acid bacterium was assimilated by propionic acid bacterium. Finally, the production of nisin A was increased two times higher by the mixed culture, comparing with the pure culture of lactic acid bacterium without pH control. Less