摘要

炭黑变色的天然产物:木素溶解酶和抗真菌挥发性化合物

白腐真菌在生态系统中发挥重要作用，主要是因为它们的细胞外酶系统和氯代芳香族化合物的产生，这些化合物充当有机物的分解者、保护真菌的抗生素、甲基供体和/或生成H2 O2氧化酶的底物。本研究以马铃薯皮(PP)和废马铃薯(DP)为营养支持材料，研究了A. discolor Sp4对木素溶解酶和抗真菌挥发性有机化合物(VOCs)的产量。锰依赖过氧化物酶(MnP)通过监测2,6 -二甲氧基苯酚的氧化来评估。除了MnP的生产，雷唑艳蓝R (RBBR)的变色也用定性测定。采用双室平板法测定了VOCs对米黑毛霉和尖孢镰刀菌的抑菌活性。最后，采用顶空固相微萃取和气相色谱质谱法对菌丝培养物释放的VOCs进行分析。MnP和MiP活性在孵育第15天达到最高(163 U L-1和24 U L-1)，并观察到RBBR完全变色。虽然两种马铃薯废弃物都具有木素溶解活性，但PP处理的MnP活性高于DP处理。在PP琼脂和DP琼脂培养基上，黄僵菌挥发物分别抑制了约62%和76%的米黑菌菌丝生长。然而，植物致病菌F. oxysporum被轻微抑制(约10%)。 The major VOCs detected were chlorinated aromatic compounds (over 50% relative area). The obtained natural products have multiple biotechnological applications among which are pollutant degradation and plant protection increase efficacy. The valorization of agro-industrial wastes as nutritional supports for producing bio-products offers farmers and agro-industry product diversification and improved environmental sustainability. The use of these wastes as substrates for microbial cultivation is currently an active field of research, allowing for energy to be saved and reducing environmental waste disposal (Dhillon et al. 2011; Obruca et al. 2015; Gopalan and Nampoothiri 2016). Some of the most interesting bio-products are biofuels and high value chemical compounds (e.g. antimicrobials, antioxidants, pigments and industrial enzymes) (Gassara et al. 2010; Hughes et al. 2014; Rodrigues et al. 2014; Schalchli et al. 2015). Different food wastes from the agro-industry and their potential recoveries have been studied, with fruits and vegetables being the most promising sources of valuable compounds (Mirabella et al. 2014). Among them, potato solid wastes (PSW) have been reported as an interesting source of carbohydrates, proteins and micronutrients that can be used as raw materials for the growth of fungi and synthesis of their bio-products (Rosales et al. 2002; Schieber and Saldaña 2009). Currently, PSW represents a disposal problem in numerous potato production and processing systems, since ~40 to 50% of the total production is unsuitable for human consumption constituting a source of plant pathogens (Charmley et al. 2006). Microbial growth is supported by media with a high content of starch (approx. 50% dry weight), which is one of the best carbon sources for some white-rot fungi (WRF) for growth and degradation of organic molecules, such as recalcitrant dyes (Revankar and Lele 2007).