用于丝状菌固态培养研究的膜培养技术

MODIFIED MEMBRANE CULTURE SYSTEM FOR RESEARCH ON SOLID-STATE FERMENTATION OF FILAMENTOUS FUNGI

提出了一种改进的膜转移培养技术 ,并以盾壳霉 (Coniothyriumminitans)的固态培养为例 ,从菌体生长、孢子产量及培养基中 pH变化等方面对该培养技术的应用价值进行了分析与研究 .结果表明 ,这种培养体系可以将菌丝体与培养基完全分开 ,但不影响菌体的正常生长与孢子形成 ;通过膜转移培养技术可将盾壳霉的孢子产量提高 1 8倍以上 ;用浸有液体培养基的脱脂棉支撑体培养体系可达到与琼脂培养体系相同的研究目的 ,但其操作更为简单 ,更利于连续培养研究 .这种培养体系在实验室条件下研究其他丝状菌的固态连续培养方面也具有很大的应用潜力 .

It is difficult to study the metabolic behavior of filamentous microorganisms in traditional solid-state fermentation systems,due to the tight integration between mycelia and medium.It is not possible either to study the kinetics of feeding and continuous strategy in this system, since the area of medium surface would change with the inflow of fresh medium.Aiming at avoiding these difficulties,a novel membrane culture system was developed.The membrane and microorganisms were transferred from one plate to another to change the medium.Another modified membrane culture system was studied by replacing agar with absorbent cotton to simplify the operation in laboratory conditions. Coniothyrium minitans was used as a model filamentous fungus to simplify the research, since the improvement of conidial production was the major aim in solid-state culture of this fungus.Production of biomass and conidia,distribution of conidia in medium, and change of pH during cultivation period were analyzed to evaluate the applicability of this novel membrane culture system.Results showed the mycelial penetration of C . minitans into the medium by using a cellulose acetate membrane with pore size of 0 45 μm, whereas the biomass production and conidial production were not affected.The conidial production was improved by 1 8 fold when the medium contents were changed during the cultivation period.The modified membrane culture system provided similar results as PDA, whereas it is more feasible and simple for the research on continuous solid state cultivation.This is the first report on the potential of membrane cultivation system in fed batch or continuous cultivation of C . minitans in solid state fermentation in laboratory conditions.The studied membrane culture system has great potential in the solid-state fermentation of other filamentous microorganisms.