Zhang Yang, Mahidul Islam Masum Md, Gao Congcong, Cheng Yudou, Guan Junfeng
Institute of Biotechnology and Food Science, Hebei Academy of Agricultural and Forestry Sciences, Shijiazhuang 050051, Hebei, China; Key Laboratory of Plant Genetic Engineering Center of Hebei Province, Shijiazhuang 050051, Hebei, China.
Institute of Biotechnology and Food Science, Hebei Academy of Agricultural and Forestry Sciences, Shijiazhuang 050051, Hebei, China; Key Laboratory of Plant Genetic Engineering Center of Hebei Province, Shijiazhuang 050051, Hebei, China; Department of Plant Pathology, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh.
Microbiol Res. 2022 Sep;262:127110. doi: 10.1016/j.micres.2022.127110. Epub 2022 Jul 1.
Microbial community structure on fruit surface plays an important role in fruit decay during postharvest storage, although the underlying mechanism has not been fully elucidated. Winter jujube (Ziziphus jujuba Miller cv. Dongzao) is a unique fruit resource with high edible and commercial value in China, while postharvest decay has always been a severe problem leading to short shelf life and poor quality of fruit. Ozone treatment is regarded as one of the most effective means to control decay and extend shelf life because of its cost-effective and eco-friendly properties. In the present study, three concentrations of ozone (2.5, 5 and 10 μL L) were found to reduce significantly postharvest decay of winter jujube on days 10 and 15, which were produced from Huanghua City, Hebei, China. High-throughput sequencing revealed significant changes in the bacterial and fungal communities in response to the application of ozone treatment, while Didymella, Rhizopus, Alternaria, Phialemoniopsis and Mycosphaerella were found to be the most abundant in fungi, and Methylobacterium, Pseudomonas, Pantoea, Sphingomonas and Gluconobacter being the most abundant in bacteria. Results of linear discriminant analysis (LDA) effect size (LEfSe) indicated that ozone treatments considerably reduced the abundance of Rhizopus and Gluconobacter on the surface of winter jujube fruit. Furthermore, Pearson correlation analysis showed that Rhizopus was positively correlated with Gluconobacter (r = 0.97) while negatively correlated with Didymella (r = -0.96). By predicting the metabolic function, ozone may inhibit metabolic pathways including nucleoside and nucleotide biosynthesis, amino acid biosynthesis, fatty acid and lipid degradation, respiration, and electron transfer, thereby reducing the incidence of fruit decay and maintaining the firmness of winter jujube fruit.
果实表面的微生物群落结构在采后贮藏期间的果实腐烂过程中起着重要作用，尽管其潜在机制尚未完全阐明。冬枣（Ziziphus jujuba Miller cv. Dongzao）是中国一种具有高食用和商业价值的独特水果资源，而采后腐烂一直是导致果实货架期短和品质差的严重问题。臭氧处理因其经济高效且环保的特性，被视为控制腐烂和延长货架期的最有效手段之一。在本研究中，发现三种浓度的臭氧（2.5、5和10 μL L）能显著降低采后第10天和第15天来自中国河北省黄骅市的冬枣的腐烂率。高通量测序显示，臭氧处理后细菌和真菌群落发生了显著变化，其中真菌中发现Didymella、Rhizopus、Alternaria、Phialemoniopsis和Mycosphaerella最为丰富，细菌中Methylobacterium、Pseudomonas、Pantoea、Sphingomonas和Gluconobacter最为丰富。线性判别分析（LDA）效应大小（LEfSe）结果表明，臭氧处理显著降低了冬枣果实表面Rhizopus和Gluconobacter的丰度。此外，Pearson相关性分析表明，Rhizopus与Gluconobacter呈正相关（r = 0.97），而与Didymella呈负相关（r = -0.96）。通过预测代谢功能，臭氧可能抑制包括核苷和核苷酸生物合成、氨基酸生物合成、脂肪酸和脂质降解、呼吸作用以及电子传递等代谢途径，从而降低果实腐烂发生率并保持冬枣果实的硬度。
