Ecological and toxicological importance of fungal diversity in pastures and potential role for novel Fusarium species in cattle mycotoxicosis

The datasets underpinned a PhD thesis titled "The mycobiota of Eastern Cape dairy pastures, including the characterisation and implications of novel Fusarium species." The researcher surveyed fungal communities in mixed pasture samples from 14 affected dairy farms. From 95 samples, 708 fungal strains were isolated and identified as 132 species across 55 genera. Fusarium was the most prevalent genus (207 strains; 21 species), followed by Penicillium, Pseudopithomyces, Cladosporium, Epicoccum, and Bipolaris. Notably, phylogenetic analyses confirmed the presence of both Pseudopithomyces toxicarius (previously reported as Pseudopithomyces chartarum) and Ps. palmicola. Among Fusarium, 155 strains belonged to the Fusarium incarnatum-equiseti species complex (FIESC). Multilocus phylogenetic analyses of TEF1-α, CaM, and RPB2 genes revealed 11 FIESC species, including five novel taxa, three of which—F. cumulatum, F. mariecurieae, and F. pascuum—researchers formally described, along with a description of F. goeppertmayerae. The researcher further examined the secondary metabolite potential of these four Fusarium species using chemical and bioinformatics-based approaches, identifying 16 secondary metabolites. From these secondary metabolites, three were identified as regulated mycotoxins (deoxynivalenol, nivalenol, and zearalenone) and nine as emerging mycotoxins (e.g., beauvericin, diacetoxyscirpenol, and equisetin). As part of the investigation into secondary metabolite potential, several core biosynthetic genes were identified, including some not associated with detectable metabolite production in vitro, highlighting the genetic capacity of these species to produce these compounds under favourable conditions.

本数据集支撑了一篇题为《东开普省奶牛牧场真菌区系及新型镰刀菌属（Fusarium）物种的特征与研究意义》的博士论文。研究者对14个受影响奶牛牧场的混合牧草样本中的真菌群落开展了调查，从95份样本中分离得到708株真菌，经鉴定分属55个属、132个物种。其中镰刀菌属（Fusarium）为最优势属，包含207株菌株、21个物种，其次依次为青霉属（Penicillium）、假皮座囊菌属（Pseudopithomyces）、枝孢属（Cladosporium）、球座霉属（Epicoccum）和平脐蠕孢属（Bipolaris）。值得注意的是，系统发育分析证实了有毒假皮座囊菌（Pseudopithomyces toxicarius，此前被报道为Pseudopithomyces chartarum）和棕榈假皮座囊菌（Ps. palmicola）的存在。在镰刀菌属中，155株菌株均属于藤红镰刀菌-木贼镰刀菌物种复合体（FIESC）；对TEF1-α、CaM和RPB2基因的多位点系统发育分析显示，该复合体包含11个物种，其中5个为新类群。研究者正式描述了其中3个新种：累积镰刀菌（F. cumulatum）、居里镰刀菌（F. mariecurieae）和牧场镰刀菌（F. pascuum），同时还完成了F. goeppertmayerae的物种描述。研究者进一步通过化学与生物信息学方法，探究了这4种镰刀菌的次生代谢产物合成潜力，共鉴定出16种次生代谢产物。其中3种为受监管的真菌毒素：脱氧雪腐镰刀菌烯醇（deoxynivalenol）、雪腐镰刀菌烯醇（nivalenol）与玉米赤霉烯酮（zearalenone）；9种为新型真菌毒素，例如白僵菌素（beauvericin）、双乙酰草镰刀菌烯醇（diacetoxyscirpenol）和木贼菌素（equisetin）。在次生代谢产物潜力研究过程中，研究者还鉴定出多个核心生物合成基因，其中部分基因在体外培养条件下未检测到对应的代谢产物合成，这表明这些物种在适宜环境下具备合成此类化合物的遗传潜能。