Study of microbiocenosis of fish gills and intestines in their cultivation using preparations based on bacteriophages

Nowadays bacteriophages are widely used in veterinary medicine, bio-technology, agriculture and in particular in aquaculture. Narrow specificity affecting the bacterial microflora and selective influence on the pathogenic and opportunistic microorganisms allow using the bacteriophages for diagnosing, preventing and treating the diseases of farm animals and fish. The emergence of antibiotic-resistant strains of microorganisms involves the search for new drugs to combat them. In this regard, phage therapy is an alternative to antimicrobial treatment of bacterial diseases of animals and fish. Despite the lack of data on the bacteriophage-based drugs applications in aquaculture, this direction is found to be promising and relevant. There is given a comparative analysis of the microbiocenosis of the gills and intestines of two-year-olds of red tilapia farmed in the water with adding the poly-valence pyobacteriophage and fed by compound feed treated by the preparation. It has been found that the dominant position in the intestinal microbiocenosis of red tilapia belongs to Micrococcus bacteria, whose share made 45.7% of all isolates of the gastrointestinal tract. By the frequency of occurrence, the second place is taken by the Bacterium species (33.2%), the third place - Staphylococcus (16.1%) species. The remaining groups of intestinal microorganisms are presented by a significantly number of isolates. It has been stated that the gills microflora was represented by a smaller species composition compared to the digestive tract microbiota. Isolates of the Bacterium and Staphylococcus bacteria were dominating, while the Actinomycetales and Bacillus microorganisms were represented in smaller numbers (1-2 colonies). The addition of a bacteriophage to water and its processing of compound feed helps to reduce the contamination of gills and reduce pathogenic microflora in the intestines of fish.

Functionalized non-woven surfaces for combating the spread of the COVID-19 pandemic

The worldwide outbreak of SARS-CoV-2 infection has necessitated mandatory use of face masks, personal protective equipment and intake of a healthy diet for immunity boosting. As per WHO's recommendation, continuous use of masks has been proven effective in decreasing the SARS-CoV-2 infection rate. The present study reports on the bacterial filtration efficacy (BFE) of a novel 4-ply functionalized non-woven face mask. We synthesized a polypropylene-based fabric with inner layers of melt-blown fine fibres coated with polylactic acid and immune-boosting herbal phytochemicals. Experimental studies on the synthesized face mask demonstrated a BFE of greater than 99% against Staphylococcus aureus (a bacterium species frequently found in mammalian respiratory tract). A thorough computational analysis using LibDock algorithm demonstrated an effective docking performance of herbal phytochemicals against harmful virus structures. More importantly, the face mask also showed sufficient and stable breathability as per regulatory standards. A breathing resistance of 30 Pa at an aerosol flow rate of 30 l h −1 was reported under standard temperature and pressure conditions, indicating a high potential for real-world applications.

Unraveling the Bacterial Assisted Degradation Pathway of Morpholine- a Xenobiotic Micropollutant: A Sustainability for Zero Pollution Environment

Biodegradation is the process by which chemicals both natural and xenobiotics are metabolized by microorganisms. Most naturally occurring chemical compounds are biodegradable while xenobiotic may be biodegradable, persistent or recalcitrant. Xenobiotic chemicals, because they are manmade and have developed recently, are present in the environment for comparatively shorter periods of time from its geological presence. This in turn means that the microbial communities present in these environments may not have evolved specific mechanisms for their degradation. Morpholine, a known xenobiotics micropollutant initially believes to be recalcitrant but later prove to be biodegradable by specific set of bacterium species most likely Mycobacterium and Pseudomonas sp in particular. However, the metabolic pathways involved in the successful biodegradation of morpholine stand challenging to establish because of its extreme water solubility and the lack of any chromophore group in morpholine which does not allow easy extraction process. Consequently, no tool for direct estimation of intermediates or metabolites of morpholine has been well reported and only indirect strategies have been developed like presence of microbial growth on intermediates, chemical/analytical assay for intermediate and ammonia measurements to elucidate the degradation pathway for zero pollution environment. In this present study degradation pathway has been ascertained by some selected bacterial isolate for their capacity to degrade morpholine. Based on the said analysis of culture filtrate, it has been revealed that the isolate namely Halobacillus utilizes glycolic route of the metabolic degradation pathway of morpholine and supports the fact that in presence of morpholine, one of two branches of morpholine biodegradation pathway namely ethanolamine and glycolate was was induced while the other branch was inhibited. Whatever the degradation pathway of morpholine exhibited by bacteria, ammonia is the end product of degradation which would be biochemically utilized by isolate.

Analysis of Transcriptomic Response to SO 2 by Oenococcus oeni Growing in Continuous Culture

Malolactic fermentation is an indispensable step in the elaboration of most wines and is generally performed by Oenococcus oeni , a Gram-positive heterofermentative lactic acid bacterium species. While O. oeni is tolerant to many of the wine stresses, including low pH and high ethanol concentrations, it has high sensitivity to SO 2 , an antiseptic and antioxidant compound regularly used in winemaking.

Влияние бактерий рода Azotobacter Chroococcum на рост и развитие пшеницы озимой в западноукраинской лесостепной провинции

The researches results showed the positive the bacterium species Azotobacter chroococcum im-pact on winter wheat yield structure. Especially, the grain yield of Favoritka increased on 0,38 t/ha, or on 10 %; weight 1000 grains – on 2.9 g, or on 7,5%; the spike’s length-on 0,7 cm or on на 9,9 %; the grain’s quantity in one spike is on 2,3 pcs, or on 9 %; one plant’s weight-on 0,23 g, or on 5,6 %; the spike’s weight-0,17g, or on11%, one spike’s grain weight- on 0,4 g, or on 5,3 %.

A Formal Model for the Simulation and Analysis of Early Biofilm Formation

Biofilms are structured communities of bacterial cells adherent to a surface. This bacterial state is called sessile.This paper focuses on the modelling of the transition between planktonic and sessile state using Real-time Maude as the modelling language. With more and more bacteria joining the sessile community, the likelihood of producing a biofilm increases. Once the percentage of bacterial cells that adheres to the surface reaches a threshold, which is specific for the considered bacterium species, a permanent biofilm is formed. An important challenge is to predict the time needed for the formation of a biofilm on a specific surface, in order to plan when the material infrastructure that comprises such a surface needs to be cleaned or replaced. We exploit the model-checking features of Real-time Maude to formally prove that a regular cleaning or replacement of the infrastructure prevents the biofilm formation.

Occurrence and Diversity of Soil Microflora in Potato Fields of Bangladesh

Microflora from potato rhizosphere soil was isolated from different potato fields of Bangladesh. Seventeen soil samples were analyzed for the presence of microflora in selected potato field soils. Seven fungal species and one bacterium species were morphologically characterized using soil dilution and streak plate methods. The predominant fungi isolated including Alternaria sp., Aspergillus sp., Penicillium sp., Rhizopus sp., Bipolaris sp., Phytophthora sp., Fusarium sp. and one bacterium was identified as Ralstonia solanacearum. Individual colonies of fungi and bacteria were counted on Potato Dextrose Agar (PDA), V8 juice Agar and their presence in soil was compared in respect of different locations of potato fields. The occurrence of Phytophthora sp. was medium in Tongibari and lower in Singair Union, Sonargaon, Matlab Dakshin, Gobindaganj, Palashbari, Gopinathpur and Bagmara. The highest counts of R. solanacearum were found in Singair Union, Tongibari and Daudkandi and the lowest counts were made in Palashbari and Bagmara. This was the first reported examination of the microbial diversity of soil microflora in some selected potato fields of Bangladesh.

Review on Pathogenic Bacteria Listeria monocytogenes, The Detection and The Sequencing Gene Methods Isolated from Meat Products

A study was conducted to review on pathogenic bacteria Listeria monocytogenes, the detection and the sequencing gene methods isolated from meat products, compare selected methods that detect the presence of Listeria monocytogenes in selected raw and processed meat products. Results indicate that Listeria monocytogenenes (originally named Bacterium monocytogenes) is a gram-positive, non-sporeforming, highly mobile, rod-type, and facultative anaerobic bacterium species. It can grow under temperatures between -1.5°C to 45°C and at pH range between 4.4 and 9.4, with the optimum pH of 7. Rapid methods (PCR based and VIDAS-LDUO®) detected Listeria monocytogenes faster than the conventional method. It was also gathered that Phenotypic identification and Genotypic identification are two types of confirmation test for Listeria monocytogenes. Listeria monocytogenenes can be found in raw meat and meat product because of environmental contamination, cross contamination or error process.

Evaluation of the Prevalence of Subclinical Mastitis in Dairy Cattle in the Soummam Valley (Bejaia, Algeria)

The present study was carried out to investigate the prevalence of subclinical mastitis (SCM) in milking cows and the effect of farming system on the prevalence of SCM”, as well as the identification of bacterial strains causing the mammary gland infection. A total of 100 dairy cows were randomly selected from 32 farms of Bejaia district (Algeria), precisely the Soummam region: from Tazmalt to El Kseur. The SCM was screened by California Mastitis Test (CMT). Milk samples were collected aseptically from (CMT) positive cows and dispatched to laboratory for further microbiological tests. Results showed that the prevalence of SCM was 26%. Moreover, no significant differences in SCM prevalence were observed between intensive and semi intensive systems (P>0.05). The Staphylococcus aureus was found to be the most frequent bacterium species associated with SCM in the cows studied.

Isolasi dan Identifikasi Bakteri Kitinolitik yang terdapat pada Cangkang Lobster Air Tawar (Cherax Quadricarinatus) [Isolation and Identification of Chytinolitic Bacteria from The Crayfish (Cherax Quadricarinatus) Shell]

AbstrakIndonesia memiliki potensi perikanan yang sangat tinggi, salah satunya adalah lobster. Ekspor lobster air tawar cenderung meningkat tiap tahun. Total ekspor hasil lobster budidaya mencapai 94.511 ton/tahun. Pangsa pasar lobster air tawar tidak hanya terbatas di dalam negeri saja tetapi juga ke luar negeri. Penelitian ini bertujuan untuk mengetahui adanya bakteri kitinolitik dan juga jenis-jenis bakteri kitinolitik yang terdapat pada cangkang lobster air tawar. Penelitian ini menggunakan Penelitian ini menggunakan metode observasi untuk mengetahui adanya bakteri kitinolitik yang ada pada cangkang lobster air tawar. Data yang digunakan dalam penelitian ini adalah secara deskriptif. Data yang diperoleh dianalisis secara deskriptif yaitu penyajian data tentang morfologi dan karakteristik dari bakteri kitinolitik yang diisolasi dari cangkang lobser air tawar (Cherax quadricarinatus) dan dibandingkan dengan morfologi dan karakteristik bakteri kitinolitik dengan literatur yang sesuai. Hasil penelitian ini adalah diperoleh bahwa bakteri yang diisolasi dari cangkang lobster air tawar (Cherax quadricarinatus) dapat tumbuh dan berkembang pada media uji. Kemudian hasil uji hidrolisis bakteri kitinolitik ditandai dengan adanya zona bening yang dihasilkan dari bakteri tersebut. Dari hasil pengujian tersebut didapatkan jenis – jenis bakteri yaitu Aeromonas sp., Bacillus sp. dan Pseudomonas sp. AbstractIndonesia have highest potential of fishery. One of them is Lobster. It has increasing slightly, approximately 94.511 ton/years. The aims this research to determine the presence of chitinolytic bacteria and identify its species in crayfish shells. This research was performed via observation method to determine the presence of chitinolytic bacteria, which are exist in crayfish (cherax quadricarinatus) shell. The data used in this research is descriptive. The data descriptively analyzed represented the morphology and characteristics of chitinolytic bacteria isolated from crayfish (Cherax quadricarinatus) and comparison the morphology and characteristics of chitinolytic bacteria with appropriate literature. These results obtained that the bacteria isolated from crayfish (Cherax quadricarinatus) shell can grow and develop in the test medium. Then, chitinolytic activity was signed by the formation of clear zone on the test medium. The results obtained several bacterium species including Aeromonas sp., Bacillus sp. and Pseudomonas sp.