Bacteria and archaea in frozen (− 20 °C) ruminal digesta were analysed by qPCR and cloning/sequencing of 16S rRNA genes. Samples frozen with and without glycerol as cryoprotectant indicated a major loss of Bacteroidetes in unprotected samples, resulting in higher proportions of Firmicutes. Archaeal numbers and diversity were unaffected.
McKain, N., Genc, B., Snelling, T. J., & Wallace, R. J. (2013). Differential recovery of bacterial and archaeal 16S rRNA genes from ruminal digesta in response to glycerol as cryoprotectant. Journal of Microbiological Methods, 95(3), 381-383. https://doi.org/10.1016/j.mimet.2013.10.009