Tenea Gabriela N, Reyes Pamela
Biofood and Nutraceutics Research and Development Group, Faculty of Engineering in Agricultural and Environmental Sciences, Universidad Técnica del Norte, Ibarra, Ecuador.
Front Microbiol. 2024 Feb 16;15:1348316. doi: 10.3389/fmicb.2024.1348316. eCollection 2024.
Strawberry ( × ) fruits are vulnerable to bacterial contamination; some species are pathogenic and can affect human health. Comprehending the bacterial composition and diversity at different ripe stages is a key determinant of the fruit health, productivity, and quality.
An amplicon metagenomic approach on the 16S rRNA region was used to identify the bacterial diversity in exocarp of fruits collected from a farm field at two ripe stages: breaking (white, phase two) and ripe (red, phase four) and purchased from different retail market stands at ripe (red, phase four, ready-to-eat) stage. Besides, the fruit quality was assessed.
Strawberries carries a high microorganisms diversity, with , and being the most abundant families across the samples. Among the groups, and were the most abundant families at breaking (phase two) and ripe (phase four), whereas , and were the most abundant families in the market group. Although samples from group four-field and market were at the same ripe stage, the bacterial species composition was divergent. spp. were prevalent (above 60%) in samples collected from the market group, and (above 70%) species were mostly found in the samples collected from the field settings regardless of the phase. Besides, and were detected in the ready-to-eat samples from both the field and the market, while was detected in the samples that originated from the market. Interestingly, and , two human opportunistic pathogens, were detected in the fruits from the market only. According to alpha and beta diversity analyses, strawberry fruits displayed significant differences ( < 0.05) in bacterial communities within the ripe group, with the samples from the market showing the most bacterial diversity. Although we do not directly correlate the quality attributes with bacterial diversity, the results indicated a clear separation between groups according with their ripe stage and origin.
This study provides a comprehensive framework of the bacterial diversity throughout the transition from unripe to ripe strawberries which may aid in the development of preventative measures to manage the postharvest contamination.
草莓果实易受细菌污染；一些细菌具有致病性，会影响人体健康。了解不同成熟阶段的细菌组成和多样性是果实健康、产量和品质的关键决定因素。
采用针对16S rRNA区域的扩增子宏基因组方法，鉴定从农田采集的处于两个成熟阶段（破果期，白色，第二阶段；成熟期，红色，第四阶段）以及从不同零售市场摊位购买的处于成熟阶段（红色，第四阶段，即食）的果实外果皮中的细菌多样性。此外，还对果实品质进行了评估。
草莓携带高度的微生物多样性， 、 和 是样本中最丰富的科。在这些类群中， 和 是破果期（第二阶段）和成熟期（第四阶段）最丰富的科，而 、 和 是市场组中最丰富的科。尽管第四组农田和市场的样本处于相同的成熟阶段，但细菌物种组成却不同。 属在市场组采集的样本中普遍存在（超过60%），无论处于哪个阶段， （超过70%）物种大多在农田采集的样本中发现。此外，在来自农田和市场的即食样本中均检测到了 和 ，而 在源自市场的样本中被检测到。有趣的是，两种人类机会致病菌 和 仅在市场的果实中被检测到。根据α和β多样性分析，草莓果实在成熟组内的细菌群落存在显著差异（ < 0.05），市场样本的细菌多样性最高。尽管我们没有直接将品质属性与细菌多样性相关联，但结果表明不同组之间根据成熟阶段和来源有明显区分。
本研究提供了一个从未成熟到成熟草莓整个过渡过程中细菌多样性的综合框架，这可能有助于制定预防措施来管理采后污染。
