黑翅土白蚁菌圃微生物对蚁巢伞生长的影响

  目的  探明黑翅土白蚁Odontotermes formosanus菌圃微生物对优势真菌蚁巢伞Termitomyces heimii生长的影响,可为深入研究白蚁菌圃微生态提供实验参考,对人工栽培蚁巢伞也具有重要参考意义。  方法  使用寡营养培养基分离菌圃微生物。细菌方面,通过探究细菌发酵液对蚁巢伞生长的影响,采用高效液相色谱法测定发酵菌液中新生成的可溶性糖类物质,初步明确菌圃细菌对蚁巢伞生长的影响;真菌方面,采用对峙培养手段探明蚁巢伞与其他菌圃真菌的互作情况。  结果  从黑翅土白蚁菌圃中共分离8种细菌及12种真菌杂菌,发现菌圃内存在大量蚁巢伞孢子。菌圃厚壁菌门Firmicutes细菌促进蚁巢伞生长,在其影响下蚁巢伞菌丝呈现纽结凸起,菌丝生长速率相比对照组极显著提高,最高提升0.033 cm·d?1(P＜0.01)。而菌圃变形菌门Proteobacteria细菌抑制蚁巢伞生长,Burkholderia sp. (待定)抑制效果最为显著,使得蚁巢伞几乎无法生长。通过高效液相色谱分析发现:菌圃细菌发酵液新生成大量可溶性糖类物质,表明菌圃细菌具备降解木质纤维素并将其转化为寡糖的能力。蚁巢伞与菌圃真菌杂菌的对峙培养表明:菌圃内真菌杂菌抑制蚁巢伞生长,一旦菌圃开始消亡,真菌杂菌(如多种霉菌)将快速占领菌圃。  结论  分离的78.9%菌圃细菌可促进蚁巢伞生长,而分离的所有真菌杂菌均抑制蚁巢伞生长,可见,菌圃微生物对蚁巢伞存在明显调控作用。图5表2参18

Impact of microorganisms of Odontotermes formosanus fungus-combs on the growth of Termitomyces heimii

  Objective  This study, with an investigation into how Odontotermes formosanus fungus-combs microorganisms influence the growth of Termitomyces heimii, is aimed to provide an experimental reference for further research on the micro-ecology of the termite combs, and make contribution to the artificial cultivation of Termitomyces.   Method  First, oligotrophic medium was employed to separate microorganisms in the fungus-combs. As for bacterium, with an exploration conducted of how bacterial fermentation broth influences the growth of T. heimii, high performance liquid chromatography (HPLC) was used to determine the newly formed soluble carbohydrates in the fermentation broths to clarify the relationship between bacterium and T. heimii. In terms of fungi, co-culture was used to detect the interaction between T. heimii and other fungi in the combs.   Result  Eight species of bacteria and 12 species of fungi were isolated from the fungus-combs where a large number of spores of T. heimii were distributed. Firmicute separated promoted the growth of T. heimii, under the influence of which, knots were formed in the hyphae and the growth rate of the hyphae partly increased by 0.033 cm·d?1 (P＜0.01). By contrast, Proteobacteria inhibited the growth of T. heimii, with a significant inhibitory effect displayed by Burkholderia sp. (undetermined) under the influence of which, T. heimii could hardly grow. As was shown in the HPLC analysis, a large amount of soluble carbohydrates were newly produced in the bacterial fermentation broths, indicating that the bacterium in the fungus-combs had the ability to degrade lignocellulose and convert it into oligosaccharides. Other fungi in the fungus-combs inhibited the growth of T. heimii and once the fungus-combs died out, fungi such as mold quickly occupied the combs.  Conclusion  78.9% of the bacterium isolated from termite combs benefits T. heimii, while all the fungi isolated inhibit its growth, implying that the microorganisms of O. formosanus fungus-combs have a significant effect on T. heimii. [Ch, 5 fig. 2 tab. 18 ref.]