Department of Microbiology, University of Stellenbosch, Stellenbosch 7600, South Africa.
Department of Bacteriology, University of Wisconsin, Madison, WI, United States.
Bioresour Technol. 2021 Feb;321:124518. doi: 10.1016/j.biortech.2020.124518. Epub 2020 Dec 9.
Rumen fluid (RF) as inocula is useful for evaluating biomass digestibility and has potential for producing volatile fatty acids (VFA) via the carboxylate platform. However, RF is not readily available, necessitating evaluation of potential preservation methods. Glycerol (50% v/v) and DMSO (5% v/v) were used to preserve rumen inocula for 3 months at -80 °C. Effects of cryo-preservation on digestibility, VFA production and community composition with β-diversity distance metrics were compared to fresh RF using apple, citrus and grape pomace as substrates. For all substrates, DMSO cryo-preserved rumen digestibility parameters, VFA yield and product distribution were more significantly comparable to fresh RF (P > 0.05) than was glycerol cryo-preserved RF. Similarly, β-diversity coefficient (unweighted unifrac) between DMSO cryo-preserved RF and fresh RF was 0.250 while the coefficient was 0.359 for the glycerol cryo-preserved RF compared to fresh RF. This showed that a DMSO cryo-preserved RF is less affected by preservation effects and is a more promising alternative to fresh RF.
瘤胃液（RF）作为接种物可用于评估生物量的消化率，并且具有通过羧酸酯平台生产挥发性脂肪酸（VFA）的潜力。然而，RF 不易获得，因此需要评估潜在的保存方法。使用甘油（50%v/v）和 DMSO（5%v/v）将瘤胃接种物在-80°C 下保存 3 个月。使用苹果、柑橘和葡萄渣作为底物，比较了冷冻保存对消化率、VFA 产量和β多样性距离指标的群落组成的影响，与新鲜 RF 进行了比较。对于所有底物，DMSO 冷冻保存的瘤胃消化率参数、VFA 产量和产物分布与新鲜 RF 更具可比性（P＞0.05），而甘油冷冻保存的 RF 则不然。同样，DMSO 冷冻保存的 RF 与新鲜 RF 之间β多样性系数（非加权UniFrac）为 0.250，而甘油冷冻保存的 RF 与新鲜 RF 之间的系数为 0.359。这表明 DMSO 冷冻保存的 RF 受保存效果的影响较小，是新鲜 RF 的更有前途的替代品。
