Molecular Mycopathology Lab., Biological Control and Cancer Research Unit, PG Department of Botany, Ramakrishna Mission Vivekananda Centenary College (Autonomous), Rahara, Kolkata, 700118, W.B., India.
Sci Rep. 2019 Feb 1;9(1):1108. doi: 10.1038/s41598-018-37108-2.
Microfungal applications are increasing daily in the medical science. Several species of Trichoderma are widely used in agricultural fields as biological control and plant growth promoting agents. The application of Trichoderma asperellum as an entomopathogenic fungus against the Anopheles mosquito, a vector of malaria, is a novel control approach. Controlling malaria with eco-friendly management practices is an urgent need. We isolated three T. asperellum from different natural sources using serial dilution and mosquito baiting techniques. The fungi were identified on the basis of phenotypical and molecular characteristics. The fungi were grown in different natural media to examine spore production ability and the fungal spore suspensions were applied to the anopheline larvae to determine their larvicidal activity in vitro. We investigated the efficacy of crude ME (methanolic extract) and different methanolic fractions (MFs) of the fungal extracts against anopheline larvae. Methanolic Fraction 8 (MF8) exhibited the strongest larvicidal activity. A GC-MS analysis of MF8 and a Chemolibrary search were performed to identify the active agents in the fungal extracts. Among the three isolates of T. asperellum, the TaspSKGN2 isolate showed the lowest LD (2.68 × 10 conidia/mL) and LT values (12.33 h). The crude ME exhibited LD values of 0.073 mg/mL and LT values of 11.33 h. MF8 showed LD values of 0.059 mg/mL and LT values of 8.57 h. In GC-MS study of MF8, 49 compounds were found. Among these, seven compounds (2,3-di hydro thiopene, p-cymene, alpha-pinene, hexadecanoic acid, 8-methyl quinoline, (Z,Z)-9,12-octa decadienoic acid, methyl ester, 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-Pyran-4-one-) with high abundance were found to have insecticidal efficacy by a literature survey. We detected a reduction in the phenoloxidase content inside the cuticle and hemolymph of the anopheline larvae after a few hours of interaction with ME (0.073 mg/mL). Thus Trichoderma asperellum has new applications for the control of Anopheles spp. malaria vectors.
医学科学中正日益广泛地应用微生物真菌。几种木霉属真菌被广泛用于农业领域，作为生物防治和植物生长促进剂。将asperellum 木霉属真菌作为一种昆虫病原真菌来防治疟疾病媒按蚊是一种新的控制方法。采用环保管理措施控制疟疾是当务之急。我们使用连续稀释和蚊子诱饵技术从不同的天然来源中分离出三种asperellum 木霉属真菌。根据表型和分子特征对真菌进行了鉴定。在不同的天然培养基中培养真菌，以检查其产孢能力，并将真菌孢子悬浮液应用于按蚊幼虫，以确定其在体外的杀幼虫活性。我们研究了粗甲醇提取物（methanolic extract，ME）和真菌提取物的不同甲醇馏分（methanolic fractions，MFs）对按蚊幼虫的功效。甲醇馏分 8（MF8）表现出最强的杀幼虫活性。对 MF8 进行 GC-MS 分析并进行化学文库搜索，以鉴定真菌提取物中的活性成分。在三种asperellum 木霉属真菌分离株中，TaspSKGN2 分离株的 LD（2.68×10 个孢子/mL）和 LT 值（12.33 h）最低。粗 ME 的 LD 值为 0.073 mg/mL，LT 值为 11.33 h。MF8 的 LD 值为 0.059 mg/mL，LT 值为 8.57 h。在 MF8 的 GC-MS 研究中，发现了 49 种化合物。其中，有 7 种化合物（2,3-二氢噻吩、对伞花烃、α-蒎烯、十六烷酸、8-甲基喹啉、（Z,Z）-9,12-十八碳二烯酸甲酯、2,3-二氢-3,5-二羟基-6-甲基-4H-吡喃-4-酮）具有杀虫功效，这是通过文献调查发现的。我们检测到在与 ME（0.073 mg/mL）接触数小时后，按蚊幼虫表皮和血淋巴中的酚氧化酶含量降低。因此，asperellum 木霉属真菌在控制疟疾病媒按蚊方面具有新的应用。
