Effects of replacing fishmeal with fermented and non‐fermented rapeseed meal on the growth,immune and antioxidant responses of red sea bream (Pagrus major)

The effect of rapeseed meal (RM) and Aspergillus oryzae fermented rapeseed meal (RM‐Koji) on red sea bream (Pagrus major) was examined. Three groups of fish (initial weight, 4.5 ± 0.02 g) were fed a basal diet (RM0) and two test diets where half of fishmeal was replaced by RM (RM50) and RM‐Koji (FRM50) for 56 days. The obtained results showed that fish fed RM0 and FRM50 exerted significantly higher growth performance, feed utilization and haemoglobin level but lower triglyceride and cholesterol than RM50 group (p < 0.05). Interestingly, except of antiprotease activity, all the immune parameters including lysozyme, respiratory burst (NBT) and bactericidal activities were significantly increased in fish fed RM0 and FRM50 diets compared to RM50 diet (p < 0.05). In addition, malondialdehyde and reactive oxygen metabolites were significantly reduced in RM0 and FRM50 groups over RM50 group (p < 0.05). The present results suggest that fermented RM induced better growth performance and immune responses than feeding red sea bream with non‐fermented RM and both RM and RM‐Koji improved the antioxidative status of fish, making RM‐Koji an interesting candidate as a functional feed for aquatic animals.     

抗黄曲霉花生种皮纹理超微结构的研究

比较分析了花生高抗、中抗和高感黄曲霉菌品种种皮纹理的超微结构。结果表明,不同的花生遗传型种皮纹理超微结构具有不同的特征且与抗黄曲霉水平有关。     

Cyclic Peptides from the Soft Coral-Derived Fungus Aspergillus sclerotiorum SCSIO 41031

Three novel cyclic hexapeptides, sclerotides C–E (1–3), and a new lipodepsipeptide, scopularide I (4), together with a known cyclic hexapeptide sclerotide A (5), were isolated from fermented rice cultures of a soft coral-derived fungus: Aspergillus sclerotiorum SCSIO 41031. The structures of the new peptides were determined by 1D and 2D NMR spectroscopic analysis, Marfey’s method, ESIMS/MS analysis, and single crystal X-ray diffraction analysis. Scopularide I (4) exhibited acetylcholinesterase inhibitory activity with an IC₅₀ value of 15.6 μM, and weak cytotoxicity against the human nasopharyngeal carcinoma cell line HONE-EBV with IC₅₀ value of 10.1 μM.     

福建省葡萄果实病害调查及微生态制剂田间应用研究

调查2019年福建省葡萄果实病害情况,并进行微生态制剂田间应用研究。对清水对照、单一施用化学药剂、单一施用微生态制剂、前期施用微生态制剂后期施用化学药剂这4种施药方式进行差异性比较,进而优化微生态制剂施药方式,以期减少化学药剂使用量。结果表明,2019年福建省酸腐病、黑曲霉病危害严重,炭疽病危害次之,灰霉病、白腐病危害相对较轻。与露地栽培模式相比,避雨栽培模式能显著降低炭疽病危害（P < 0.05）。前期施用微生态制剂后期施用化学药剂的施药方式能显著降低酸腐病发病率并显著增加百粒重,减少化学药剂施用量。建议福建省在葡萄栽培过程中须重视对酸腐病、黑曲霉病的防治,加大避雨栽培模式的推广力度,并合理应用微生态制剂进行葡萄果实病害绿色防控。     

黑曲霉超临界萃取物抑制链格孢作用机制的初步研究

本试验对黑曲霉菌丝体超临界萃取物(SE)抑制链格孢的机制进行了初步研究。采用超临界萃取从黑曲霉菌丝体中获得样品SE,使用气相色谱-质谱(GC-MS)对其萃取物进行分离鉴定,并通过细胞膜渗透性测定、核酸和总蛋白含量测定、4′,6-二脒基-2-苯基吲哚(DAPI)荧光染色法、活性氧(ROS)含量测定、呼吸代谢途径等方法对SE的抑菌机制进行研究;电导率及核酸、蛋白结果显示,SE能影响链格孢细胞膜的完整性,SE处理菌体4.5 h,电导率比阴性对照增加了37.2%,胞外核酸蛋白含量显著增加。DAPI染色结果显示,DAPI可以和链格孢内的核酸结合,经SE作用30 min,SE可引起细胞核染色质异常弥散。ROS试验结果显示,SE可以激发菌体产生过多的活性氧,SE作用链格孢40 min时ROS含量比阴性对照增加了79.67%。呼吸代谢试验结果显示,SE能抑制三羧酸循环(TCA)中的琥珀酸脱氢酶的活性,其抑制率为35.4%。SE具有较强的抑菌活性,其抑菌机制是通过影响细胞膜的正常功能、损伤细胞结构和抑制真菌的呼吸代谢等方面实现的。     

一株猪粪降解菌的筛选、评价及鉴定

发酵床是目前国内规模化养猪企业广泛采用的粪污处理模式,其关键在于投加的微生物菌剂。为了分离出能高效降解猪粪的菌株,采用NH₃选择性培养基对土壤微生物菌株进行初筛,共得到7株氨氮降解率大于70%的菌株。通过猪粪发酵模拟实验对分离株的NH₃抑制效果进行初步评价,结果表明,7株菌株均能不同程度地减少猪粪发酵过程中氨的释放量,其中Z10菌株的NH₃抑制效果最为显著。针对猪粪除臭及促进猪粪腐熟效果开展了Z10菌株应用效果评价。除臭试验结果显示,Z10菌株对猪粪臭气中NH₃与H₂S均有较好的抑制作用,在21 d发酵周期内, NH₃与H₂S的释放量较对照组分别减少了38.66%与50.03%。促腐熟试验结果显示,Z10组种子发芽率与发芽指数分别达到了83.33%与88.55%,而对照组发芽率与发芽指数仅为68.35%与59.12%。生化鉴定显示,Z10菌株无蛋白酶活性,具有较弱的糖化酶、淀粉酶及脂肪酶的活性,但表现出较强纤维素降解活力,其纤维素酶活力达到232.543 U·mL^-1,推测Z10菌株表现出的促腐熟效果主要源于其高纤维素降解活力。16S rDNA分子鉴定结果显示该菌为烟曲霉菌(Aspergillus fumigatus)。     

Mitochondrial Targeting in an Anti-Austerity Approach Involving Bioactive Metabolites Isolated from the Marine-Derived Fungus Aspergillus sp.

The tumor microenvironment is a nutrient-deficient region that alters the cancer cell phenotype to aggravate cancer pathology. The ability of cancer cells to tolerate nutrient starvation is referred to as austerity. Compounds that preferentially target cancer cells growing under nutrient-deficient conditions are being employed in anti-austerity approaches in anticancer drug discovery. Therefore, in this study, we investigated physcion (1) and 2-(2′,3-epoxy-1′,3′,5′-heptatrienyl)-6-hydroxy-5-(3-methyl-2-butenyl) benzaldehyde (2) obtained from a culture extract of the marine-derived fungus Aspergillus species (sp.), which were isolated from an unidentified marine sponge, as anti-austerity agents. The chemical structures of 1 and 2 were determined via spectroscopic analysis and comparison with authentic spectral data. Compounds 1 and 2 exhibited selective cytotoxicity against human pancreatic carcinoma PANC-1 cells cultured under glucose-deficient conditions, with IC₅₀ values of 6.0 and 1.7 µM, respectively. Compound 2 showed higher selective growth-inhibitory activity (505-fold higher) under glucose-deficient conditions than under general culture conditions. Further analysis of the mechanism underlying the anti-austerity activity of compounds 1 and 2 against glucose-starved PANC-1 cells suggested that they inhibited the mitochondrial electron transport chain.     

澧县‘红地球’葡萄表面黑色组曲霉种群结构及产毒情况研究

葡萄和葡萄制品面临着真菌毒素的威胁, 这些真菌毒素主要来自于黑色组曲霉Aspergillus section Nigri?本研究对采自湖南省澧县‘红地球’葡萄上的黑色组曲霉进行了分离鉴定及种群结构分析, 并采用超高效液相色谱串联质谱技术(ultra performance liquid chromatography-tandem mass spectrometry, UPLC-MS/MS)对12株代表菌株产赭曲霉毒素(ochratoxin A, OTA)和伏马毒素B2(fumonisin B2, FB2)的能力进行了测定?结果表明, 澧县地区‘红地球’葡萄带菌率为92%?基于钙调素序列, 分离得到的131株黑色组曲霉分属于5个种, 其中A.aculeatinus为优势种?12株代表菌株均不产生OTA; A.welwitschiae(4/5)及A.niger(2/2)可产生FB2, 平均产毒量分别为3.36 ng/g及741.37 ng/g?上述结果为评估国内葡萄表面黑色组曲霉及其毒素的污染风险提供参考?     

九种植物精油对黄曲霉抑制作用的比较

为筛选高效抑制黄曲霉的植物精油,采用固体培养和液体培养相结合的方式从黄曲霉生长速率及延滞期、菌体超微结构、黄曲霉毒素B1合成量等方面比较了9种植物精油（川穹、肉桂、大茴香、安息香、丁香、香茅、芫荽、百里香、柠檬草精油）对黄曲霉的抑制效果。结果表明：肉桂精油的抑菌效果最强,对黄曲霉生长和产毒的抑制率达100%,其次为柠檬草、丁香、百里香精油,能使黄曲霉生长的延滞期从(0.02±0.01) d延长至(11.27±0.34)~(12.64±0.08) d,并使生长速率降低了91.43%~97.83%,黄曲霉毒素B1合成量下降了86.74%~88.40%,同时观察到这4种精油对黄曲霉菌丝体和孢子造成严重损伤,引起细胞塌陷收缩,内容物泄漏。说明肉桂、柠檬草、丁香、百里香精油能有效抑制黄曲霉类真菌,可用于食品中黄曲霉类真菌及其毒素的控制。     

脉冲强光诱变对黑曲霉产果胶酶活力的影响

脉冲强光技术可应用于微生物诱变育种以及获得高产菌株。该文采用响应面法确定脉冲强光诱变黑曲霉高产果胶酶的最佳条件,同时探究突变菌株高产果胶酶的酶学性质。结果表明:脉冲强光诱变条件为脉冲电压2075 V,脉冲次数36次,脉冲距离5.4 cm。以此工艺参数进行诱变,得到了高产果胶酶的突变菌株L9,与原始菌株相比,其果胶酶活力提高了82.22%±0.18%。突变菌株L9遗传性能良好,所产果胶酶具有更高的pH稳定性和热稳定性。因此,脉冲强光可用于黑曲霉诱变,得到稳定性良好的高产果胶酶的突变菌株。