The gut microbiota in pigs: ecology and biotherapeutics

The community of microorganisms inhabiting the intestine of mammals are referred to as the gut microbiome and are known to influence the health of their host. Despite extensive work in the last decades, we still know remarkably little about their diversity and the molecular mechanisms underlying interactions with the host. After reviewing the main methods used to analyse gut microbiomes, we summarize data on the structural and functional diversity of the microbial ecosystem in pigs and also highlight the potential of cultivation and applications based on the use of minimal bacterial consortia.

Bioremediation of Cutting Pits by Autochtonous Bacteria-Fungi Consortia

The aim of this work is to verify the potential of a consortium of autochthonous bacteria and fungi, isolated from samples of contaminated soils and water collected in a site containing cutting pits muds, in order to evaluate enhancing in biodegradation of hydrocarbons content. This innovative technique would take advantage of the synergistic effect of bacteria and fungi. In addition, this technique would allow to avoid the introduction of commercial allochthonous microflora for soil remediation and the use of chemical products for tool cleaning. Samples retrieved from a production site were used to isolate bacterial and unicellular fungal species able to grow on hydrocarbons were demonstrated to be able to degrade light and "diesel-like" hydrocarbons under laboratory conditions and in liquid cultures in less than a month. The activity of the consortium was also tested on crude oil, showing an overall degradation of the analyzable fraction greater of sixty percent after a 14-day incubation. Low C number linear hydrocarbons were the preferred substrate, but also cycloalkanes and mono- and di-aromatics seemed to be a good growth substrate. Probably, the action of enzymes secreted by fungal strains could enhance the degradation of complex molecules such as polycyclic aromatic hydrocarbons. Lab tests of consortium efficiency on mud samples are ongoing and an on-site pilot test is foreseen, to prove the activity of the consortium under the challenging field conditions. The development of fungal and bacterial consortia for degradation of complex hydrocarbon mixtures will represent an innovative approach that combines the action of enzymes secreted by fungi followed by the bacterial breakdown, a synergistic effect which could potentially increase the rate and effectiveness of hydrocarbons decontamination.

Presence of Hydrocarbon Degrading Bacteria in Contaminated Soil Collected From Various Fuel Station in Bhilai, Chhattisgarh

In this study, we isolated seven strains (termed BY1–7) from polluted soil at an oil station and evaluated their abilities to degrade total petroleum hydrocarbons (TPHs). Among 45 bacterial colonies one bacterial strain was identified based on the cultural, morphological and biochemical characteristics. The isolated bacterium was then subjected to a preliminary assessment of their crude oil after 48 hours of incubation on nutrient agar plates overlaid with 100 ML of petroleum crude oil, the zone of clearance was observed. The isolated bacteria showed 35% petrol degradation, whereas a relatively high oil degradation rate, almost 40% was observed when the bacterium was acclimatized. The selected bacterial strains crude oil resistance was analysed based on the growth ability on the crude oil containing mediums. This strain was identified as Brevibacterium brevis. After inoculation, growth ability was measured and the highest percentage of petrol degradation occurred at temperature 37 °C with the value 30.8%. Bacteria displaying such capabilities are often exploited for the bio-remediation of petroleum oil contaminated environments. Recently, microbial remediation technology has developed rapidly and achieved major gains. However, this technology is not omnipotent. It is affected by many environmental factors that hinder its practical application, limiting the large-scale application of the technology. Keywords: Petroleum hydrocarbon-degrading Bacteria, Petroleum oil, Bio-remediation, Bacterial consortia, Environmental factors, Enzymes.

A Mini-Review on the Co-growth and Interactions Among Microorganisms (Fungi and Bacteria) From Rhizosphere of Metal-Hyperaccumulators

The co-growth and synergistic interactions among fungi and bacteria from the rhizosphere of plants able to hyper accumulate potentially toxic metals (PTMs) are largely unexplored. Fungi and bacteria contribute in an essential way to soil biogeochemical cycles mediating the nutrition, growth development, and health of associated plants at the rhizosphere level. Microbial consortia improve the formation of soil aggregates and soil fertility, producing organic acids and siderophores that increase solubility, mobilization, and consequently the accumulation of nutrients and metals from the rhizosphere. These microorganism consortia can both mitigate the soil conditions promoting plant colonization and increase the performance of hyperaccumulator plants. Indeed, microfungi and bacteria from metalliferous soils or contaminated matrices are commonly metal-tolerant and can play a key role for plants in the phytoextraction or phytostabilization of metals. However, few works deepen the effects of the inoculation of microfungal and bacterial consortia in the rhizosphere of metallophytes and their synergistic activity. This mini-review aimed to collect and report the data regarding the role of microbial consortia and their potentialities known to date. Moreover, our new data had shown an active fungal-bacteria consortium in the rhizosphere of the hyperaccumulator plant Alyssoides utriculata.

Establishing and Optimizing a Bacterial Consortia for Effective Biodegradation of Petroleum Contaminants: Advancing Classical Microbiology via Experimental and Mathematical Approach

In classical microbiology, developing a high-efficiency bacterial consortium is a great challenge for faster biodegradation of petroleum contaminants. In this study, a systematic experimental and mathematical procedure was adopted to establish a bacterial consortium for the effective biodegradation of heavy oil constituents. A total of 27 bacterial consortia were established as per orthogonal experiments, using 8 petroleum-degrading bacterial strains. These bacteria were closer phylogenetic relatives of Brevundimonas sp. Tibet-IX23 (Y1), Bacillus firmus YHSA15, B. cereus MTCC 9817, B. aquimaris AT8 (Y2, Y6 and Y7), Pseudomonas alcaligenes NBRC (Y3), Microbacterium oxydans CV8.4 (Y4), Rhodococcus erythropolis SBUG 2052 (Y5), and Planococcus sp. Tibet-IX21 (Y8), and were used in different combinations. Partial correlation analysis and a general linear model hereafter were applied to investigate interspecific relationships among different strains and consortia. The Y1 bacterial species showed a remarkable synergy, whereas Y3, Y4, and Y6 displayed a strong antagonism in all consortia. Inoculation ratios of different strains significantly influenced biodegradation. An optimal consortium was constructed with Y1, Y2, Y5, Y7, and Y8, which revealed maximum degradation of 11.238 mg/mL OD600 for oil contaminants. This study provides a line of evidence that a functional consortium can be established by mathematical models for improved bioremediation of petroleum-contaminated environment.