Influence of the densities and nutritional components of bacterial colonies on the culture-enriched gut bacterial community structure

Abstract

Isolating relevant microorganisms is still a substantial challenge that limits the use of bacteria in the maintenance of human health. To confirm which media and which bacterial colony densities can enrich certain kinds of bacteria, we selected eight common media and used them to enrich the gut microorganisms on agar plates. Then, we calculated the numbers of bacterial colonies and collected the bacterial culture mixtures from each kind of medium. Using the Illumina HiSeq platform, we analyzed the composition and diversity of the culture-enriched gut bacterial community. Our data suggested that medium supplemented with blood could increase the diversity of the bacterial community. In addition, beef powder and peptone could significantly change the culture-enriched bacterial community. A moderate density (100–150 colony-forming units per plate) was optimal for obtaining the highest diversity on the agar. Similarly, membrane transport was significantly enriched in the moderate-density group, which indicated a more active metabolism in this density range. Overall, these results reveal the optimal culture conditions, including the densities of colonies and nutritional components for various gut bacteria, that provide a novel strategy for isolating bacteria in a way that is targeted and avoids blinded and repetitive work.

Reactive granulopoiesis depends on T-cell production of IL-17A and neutropenia-associated alteration of gut microbiota

“…The only genus increased both in SCT-induced and chemotherapy-induced neutropenia was Ruminococcaceae UCG-014 that was not significantly increased after short-term neutropenia after BMT. Although this genus is not culturable and the detailed biological functions remain largely unknown, bacteria belonging to Ruminococcaceae are major components of a healthy gut microbiota and major producers of SCFAs ( 53 , 54 ). Multiple species belonging to Ruminococcaceae along with species in Clostridium , Bacteroides , and Bifidobacterium were included in the 20-strain mixture which was isolated from human stool samples as potent IL-17A inducers ( 39 ).…”

Advances in Culturomics Research on the Human Gut Microbiome: Optimizing Medium Composition and Culture Techniques for Enhanced Microbial Discovery

“…Additionally, beef powder, which is rich in essential proteins and amino acids, plays a crucial role as a nutritional source for promoting microbial growth. The presence or absence of beef powder is suggested to be a decisive factor in determining the rate and success of microbial growth [ 34 , 35 ]. Mucin, the main component of the mucus layer in the gastrointestinal tract, provides an environment that mimics the host gut.…”

Enzyme-producing symbiotic bacteria in gastropods and bivalves molluscs: Candidates for bioindustry materials

“…The difference in growth in the test media occurred due to the nutrients contained. According to Gu et al (2021), the differences in the growth of bacterial colonies were caused by variations in the density of bacterial cells and the availability of nutrients in the culture media. Bacterial characterization was carried out after isolation and before purification to enable better observation of the shape of the colonies' growth.…”