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The purpose of the current study was to evaluate the impact of various doses of microencapsulated lemongrass and mangosteen peel (MELM) on gas dynamics, rumen fermentation, degradability, methane production, and microbial population in in vitro gas experiments. With five levels of microencapsulated-phytonutrient supplementation at 0, 1, 2, 3, and 4% of substrate, 0.5 g of roughage, and a concentrate ratio of 60:40, the trial was set up as a completely randomized design. Under investigation, the amount of final asymptotic gas volume was corresponding responded to completely digested substrate (b) increased cubically as a result of the addition of MELM (P < 0.01) and a cubic rise in cumulative gas output. The amount of MELM form did not change the pH and NH3-N concentration of the rumen after 12 and 24 h of incubation. However, methane production during 24 h of incubation, the levels were cubically decreased with further doses of MELM (P < 0.01) at 12 h of incubation. Increasing the dosage of MELM supplementation at 2% DM resulted in a significant increase in the digestibility of in vitro neutral detergent fiber (IVNDF) and in vitro true digestibility (IVTD) at various incubation times (P < 0.05), but decreased above 3% DM supplementations. Moreover, the concentration of propionic acid (C3) exhibited the variations across the different levels of MELM (P < 0.05), with the maximum concentration obtained at 2% DM. The populations of Fibrobacter succinogenes, Ruminococcus albus, Ruminococcus flavefaciens, and Megasphaera elsdenii revealed a significant increase (P < 0.05), while the quantity of Methanobacteriales decreased linearly with increasing doses of MELM. In conclusion, the inclusion of MELM at a concentration of 2% DM in the substrate which could enhance cumulative gas production, NDF and true digestibility, C3 production, and microbial population, while reducing methane concentration and Methanobacterial abundance. [ABSTRACT FROM AUTHOR]

Cooperation via shared public goods is ubiquitous in nature, however, noncontributing social cheaters can exploit the public goods provided by cooperating individuals to gain a fitness advantage. Theory predicts that this dynamic can cause a Tragedy of the Commons, and in particular, a 'Collapsing' Tragedy defined as the extinction of the entire population if the public good is essential. However, there is little empirical evidence of the Collapsing Tragedy in evolutionary biology. Here, we experimentally demonstrate this outcome in a microbial model system, the public good-producing bacterium Pseudomonas aeruginosa grown in a continuous-culture chemostat. In a growth medium that requires extracellular protein digestion, we find that P. aeruginosa populations maintain a high density when entirely composed of cooperating, protease-producing cells but completely collapse when non-producing cheater cells are introduced. We formulate a mechanistic mathematical model that recapitulates experimental observations and suggests key parameters, such as the dilution rate and the cost of public good production, that define the stability of cooperative behavior. We combine model prediction with experimental validation to explain striking differences in the long-term cheater trajectories of replicate cocultures through mutational events that increase cheater fitness. Taken together, our integrated empirical and theoretical approach validates and parametrizes the Collapsing Tragedy in a microbial population, and provides a quantitative, mechanistic framework for generating testable predictions of social behavior. [ABSTRACT FROM AUTHOR]

To assess the possible impact of climatic variation on microbial community composition in organic winemaking, we employed a metabarcoding approach to scrutinize the microbiome in a commercial, organic, Pinot noir wine production system that utilizes autochthonous fermentation. We assessed microbial composition across two vintages (2018 and 2021) using biological replicates co-located at the same winery. Microbial dynamics were monitored over four important fermentation time points and correlated with contemporaneous climate data. Bacterial (RANOSIM = 0.4743, p = 0.0001) and fungal (RANOSIM = 0.4738, p = 0.0001) compositions were different in both vintages. For bacteria, Lactococcus dominated the diversity associated with the 2018 vintage, while Tatumella dominated the 2021 vintage. For fungal populations, while Saccharomyces were abundant in both vintages, key differences included Starmerella, copious in the 2018 vintage; and Metschnikowia, substantive in the 2021 vintage. Ordination plots correlated the climatic variables with microbial population differences, indicating temperature as a particularly important influence; humidity values also differed significantly between these vintages. Our data illustrates how climatic conditions may influence microbial diversity during winemaking, and further highlights the effect climate change could have on wine production. [ABSTRACT FROM AUTHOR]