Major Groups Of Microorganisms Research Articles

A critical review on occurrence, distribution, environmental impacts and biodegradation of microplastics

Microplastics are small plastic particles (<5mm) linked by hydrocarbon atoms. Microplastics are of two types: primary microplastics, which are inadvertently released into the ecosystem as microbeads, plastic pellets and plastic fibres and secondary microplastics, derived from primary microplastics, when macroplastics get decomposed in the presence of UV light or weathering. Sources of contamination by microplastics can be classified as Terrestrial sources and Aquatic Sources. Microplastics are widespread in diverse ecosystems and are spread in different parts of the world, like India, China, Brazil and Malaysia. Recent studies have revealed the toxic effects of microplastics on various biotic and abiotic components. Microplastics can be completely removed from the soil by microbial biodegradation, most preferably bacteria, actinobacteria and fungi. Bacteria, the recurring group of microbes, can degrade pollutants. Actinobacteria, a commonly occurring Gram-positive bacterium, degrade polymer accumulation. Followed by bacteria, fungi are a major group of microorganisms known to degrade microplastics. The current review deals with the type of plastics, their sources, distribution, environmental impacts and degradation using biological methods, preferably microbes, which would further help in understanding the microplastic-mediated adverse effects' molecular mechanism and their removal from the environment using Green Technology. Key words: Biodegradation, Microbes, Microplastics, Toxicity

The Role of Yeasts and Lactic Acid Bacteria on the Metabolism of Organic Acids during Winemaking.

The main role of acidity and pH is to confer microbial stability to wines. No less relevant, they also preserve the color and sensory properties of wines. Tartaric and malic acids are generally the most prominent acids in wines, while others such as succinic, citric, lactic, and pyruvic can exist in minor concentrations. Multiple reactions occur during winemaking and processing, resulting in changes in the concentration of these acids in wines. Two major groups of microorganisms are involved in such modifications: the wine yeasts, particularly strains of Saccharomyces cerevisiae, which carry out alcoholic fermentation; and lactic acid bacteria, which commonly conduct malolactic fermentation. This review examines various such modifications that occur in the pre-existing acids of grape berries and in others that result from this microbial activity as a means to elucidate the link between microbial diversity and wine composition.

Cadmium Pollution Impact on the Bacterial Community of Haplic Cambisols in Northeast China and Inference of Resistant Genera

Modern industry and agriculture has aggravated heavy metal pollution of soils, of which cadmium (Cd) is among the common most toxic and widely distributed pollutants. Bacteria are a major group of microorganisms and the most abundantly occurring in soils. In Northeastern China, many mining sites occur whose soils need reclamation and Cd pollution has commonly existed. Haplic Cambisols is the zonal forest soil here. Yet, how Cd contamination may affect the bacterial characteristics and chemical properties of Haplic Cambisols is still unknown. Here, we applied different concentrations of Cd contamination to Haplic Cambisols and monitored the resulting changes to bacterial community structure and diversity, as well as the general soil environments; we then inferred Cd-resistant bacteria to provide theoretical support for microbial remediation of Cd-contaminated Haplic Cambisols in Northeast China. Haplic Cambisols were treated with different concentrations of CdCl2 solutions (0 [CK], 1, 5, 25, 50, 75, 100 mg kg−1, respectively expressed as T1, T2, T3, T4, T5, and T6) and incubated for 50 days, and then bacterial community composition was identified, and the pH, organic matter, hydrolytic nitrogen, available phosphorus, potassium, and cadmium contents of the soils were measured. Adding higher concentrations of Cd usually significantly increased the richness and diversity of the bacterial community in Haplic Cambisols in terms of both species and abundance with the effects of some treatments being not significant, and this effect varied with Cd concentration. Applying Cd significantly influenced the bacterial community’s structure and its metabolic functioning. Cd also influenced bacterial diversity via several key soil environmental factors, namely the pH, organic matter, and hydrolytic nitrogen contents. Pseudolabrys, Ralstonia, Reyranella, Afipia, Pelomonas, Rhizomicrobium, and Bradyrhizobium within Proteobacteria; Rhodanobacter from Bacteroidetes; and Nitrobacter within Nitrospirae were the main resistant bacteria. Higher concentrations of Cd increased the bacterial community richness and diversity of Haplic Cambisols, as well as the relative abundance of their main bacterial populations. The Cd-resistant genera were inferred, and relative abundances of Ralstonia, Bradyrhizobium, Rhizomicrobium, and Afipia were the highest.

English

Tchoukoutou is a traditional sorghum opaque beer produced and consumed in Benin. It is obtained from an uncontrolled fermentation of sorghum wort using a traditional starter called “kpete-kpete”. The present study assessed the effects of storage duration on the physicochemical and microbiological characteristics as well as on the functional properties of the heat stabilized starter produced from “kpete-kpete”. The physicochemical characteristics of the stabilized starter were not significantly affected by the storage duration. After 60.0 days of storage, the dry matter, pH and titratable acidity were stable with mean values of 92.5%, 4.76 and 1.33 g/kg, respectively. However, the microbial characteristics of the product were significantly affected by the storage duration. Yeasts, lactic acid bacteria (LAB) and total mesophilic aerobic counts were modified following three phases: a latency phase (between 0 and 10 days), an exponential growth phase (between 10 and 40 days) and the decline phase (between 40 and 60 days). As compared to the stabilized starter, the physicochemical characteristics of “kpete-kpete’’ were extensively modified after 15 days of storage. In the traditional “kpete-kpete’’, all the major groups of microorganisms, reached their maximum growth phase after 10 days of storage suggesting that they would have lost their fermentation power afterwards. The fermentation test performed using stabilized starter sampled at different growth phases, revealed that the starter of 25 days of storage possesses better fermentation capacity. In these conditions, the fermentation duration was reduced to 16 instead of 24 h. Key words: Sorghum, opaque beer, tchoukoutou, starter, storage duration.

ESTIMATION OF MICROBIAL BURDEN DUE TO DIFFUSED AND POINT SOURCES AT SPATIAL SCALE IN MIDDLE STRETCH OF RIVER BHAVANI, COIMBATORE, TAMILNADU

This study was aimed to estimate the microbiological status of river Bhavani which is the major life line of the surrounding area. The river water is used mainly for drinking, washing and swimming purposes. Water samples were collected from five sites (Pilloor, Effluent, Sweage I & II, Bhavanisagar reservoir) and theresults obtained were compared with WHO and EP standards for drinking and recreational water. In the present investigation station III and IV (which is Sweage I & II respective points) showed more numbers of microbes were present which cause the deadly diseases to human being as well as in aquatic, terrestrialorganism due the sewage discharges from the nearby towns. But in the case of lower stream (Bhavanisagar reservoir) that the counts of microorganism present in the reservoir was slightly reduced. The major groups of microorganisms were isolated and identified are E. coli, P. aerugionosa, E. aerogenes, S. aureus, Salmonella sp, Bacillus sp, Proteus sp, Klebsiella sp, Flavo bacterium, Acinetobacter sp. The results are alarming and show that alternative measures to reduce the pollution should be taken in favor of society

NATURAL MICROFLORA OF WINE GRAPE BERRIES

The diversity of yeasts and bacterial species on grapes has been investigated in vineyards worldwide. For winemaking are very important three groups of microorganisms. First two includes acetic acid and lactic acid bacteria; they live and grow normally on grape surface. The third group includes more than 20 detectable genera of yeasts. There are three principal genera found on grapes Hanseniaspora uvarum (Kloeckera apiculata), Metschnikowia pulcherrima (Candida pulcherrima), and Candida stellata or new descripted Candida zemplinina. Aim of this study was investigate of number of three major groups of microorganisms which are important for grapes and winemaking. The number of bacteria on Acetobacter agar (AA) ranged from 1.76 log CFU/mL to 2.80 log CFU/mL. Lactic acid bacteria were counted on MRS agar and the number of detectable colonies ranged from 0.48 log CFU/mL to 2.06 log CFU/mL. Sabouraud dextrose agar (SDA) was used for cultivation of yeast and the number of yeasts ranged from 2.47 log CFU/mL to 2.76 log CFU/mL. For identification of yeast species were used different types of agar media with acid base indicator bromocresol green. Identified 10 yeasts species includes to genus: Candida, Metschnikowia, Pichia, Kluyveromyces, Hanseniaspora, Hansenula, Candida, Debaromyces, Rhodotorula and Saccharomyces. We identified only few bacterial species includes to genus Lactobacillus, Pediococcus, Gluconobacter and Acetobacter.

Evolution of the Dominant Groups of Micro-organisms during the Composting Process of the Household Refuses from the Dschang Municipality – Cameroon

Aims: This study was aimed at identifying and characterizing the different microbial groups that are involved in the composting process of household waste from the city of Dschang. Study Design: Three compost heaps of household wastes were studied, and a composite sample was collected once every two weeks during the four months period for microbiological analysis. Place and Duration of Study: The Household Waste Composting Pilote Project of the Dschang Original Research Article Temgoua et al.; BMRJ, 8(1): 348-357, 2015; Article no.BMRJ.2015.127 349 municipality, during the four months study period. Methodology: The total bacterial and fungal microflora have been identified according to the suspensions-dilutions technique on a specific solid medium, incubated and then counted. The confirmation test for fungi was the methylene blue. Results: Three major groups of microorganisms were present in the compost from household waste from the Dschang municipality that we studied: Bacteria, Actinomycetes and Fungi. The density of bacteria decreases with the phases of the composting while actinomycetes and fungi are increasing. Among the microbial strains identified, some are present in all the composting phases (Pseudomonas, Penicillium, Rhizopus and Nocardia), others disappear in the cooling phase (Mucor spp) and others finally appear only at the phase of maturation (Saccharomycetes). Conclusion: The evolution of fungal and bacterial diversity during the composting process is parallel to that of their density because the maintenance, the disappearance or appearance of certain strains can be explained by the variation in the temperature, moisture, pH, biodegradable organic matter and competitions between the microbial strains.

Shifting the paradigm from pathogens to pathobiome: new concepts in the light of meta-omics

The concept of pathogenesis has evolved considerably over recent years, and the scenario “a microbe + virulence factors = disease” is probably far from reality in a number of cases. Actual pathogens have extremely broad biological diversity and are found in all major groups of microorganisms (viruses, bacteria, fungi, protozoa…). Their pathogenicity results from strong and often highly specific interactions they have with either their microbial environment, hosts and/or arthropod vectors. In this review, we explore the contribution of metagenomic approaches toward understanding pathogens within the context of microbial communities. With this broader view, we discussed the concept of “pathobiome” and the research questions that this raises.

Ecological-physiological diversity of microbial communities in the anthropogenically impacted landscapes of Kuzbass

Data on the viable pool of microorganisms detected in the upper layer of technogenic soils formed on coal dumps, ash dumps and ore slurries are presented. The ecophysiological features of oligotrophic bacteria communities have been revealed; tiny colonial forms and biofilms of prokaryotes have been detected; the effect of recultivation and soil improvers on the composition of the major groups of microorganisms has been shown.

Biological breakdown of wood in buildings

A review is given of the role of fungi in nature and in buildings. The major groups of microorganisms are presented, and the living conditions of wood-decaying fungi regarding temperature and moisture are described. Both constructional and chemical methods of wood protection are options when wanting to avoid fungal decay. In Denmark, houses can be insured against fungal decay. Moulds affect both indoor climate and people and can cause a range of different health problems, such as allergies and infections. They produce large numbers of spores as well as volatile organic compounds. Mould growth can be controlled by steam treatment and the use of different disinfectants.

Combined Phospholipid Biomarker-16S rRNA Gene Denaturing Gradient Gel Electrophoresis Analysis of Bacterial Diversity and Physiological Status in an Intertidal Microbial Mat

A combined lipid biomarker-16S rRNA gene denaturing gradient gel electrophoresis analysis was used to monitor changes in the physiological status, biomass, and microbial composition of a microbial mat. In the morning hours, an increase in the biomass of layers containing a high density of phototrophs and a decrease in the growth rate in the deep layers were observed. The combined approach also revealed differences in major groups of microorganisms, including green nonsulfur, gram-positive, and heterotrophic bacteria.

Long-Term Manipulations of Intact Microbial Mat Communities in a Greenhouse Collaboratory: Simulating Earth's Present and Past Field Environments

Photosynthetic microbial mat communities were obtained from marine hypersaline saltern ponds, maintained in a greenhouse facility, and examined for the effects of salinity variations. Because these microbial mats are considered to be useful analogs of ancient marine communities, they offer insights about evolutionary events during the >3 billion year time interval wherein mats co-evolved with Earth's lithosphere and atmosphere. Although photosynthetic mats can be highly dynamic and exhibit extremely high activity, the mats in the present study have been maintained for >1 year with relatively minor changes. The major groups of microorganisms, as assayed using microscopic, genetic, and biomarker methodologies, are essentially the same as those in the original field samples. Field and greenhouse mats were similar with respect to rates of exchange of oxygen and dissolved inorganic carbon across the mat-water interface, both during the day and at night. Field and greenhouse mats exhibited similar rates of efflux of methane and hydrogen. Manipulations of salinity in the water overlying the mats produced changes in the community that strongly resemble those observed in the field. A collaboratory testbed and an array of automated features are being developed to support remote scientific experimentation with the assistance of intelligent software agents. This facility will permit teams of investigators the opportunity to explore ancient environmental conditions that are rare or absent today but that might have influenced the early evolution of these photosynthetic ecosystems.

Molecular Ecological Analysis of Methanogens and Methanotrophs in Blanket Bog Peat.

Abstract Methane production and methane oxidation potential were measured in a 30 cm peat core from the Moorhouse Nature Reserve, UK. The distribution of known groups of methanogens and methane oxidizing bacteria throughout this peat core was assessed. Using 16S rRNA gene retrieval and functional gene probing with genes encoding key proteins in methane oxidation and methanogenesis, several major groups of microorganisms were detected. Methane production and oxidation was detected in all depths of the peat core. PCR amplification and oligonucleotide probing experiments using DNA isolated from all sections of the peat core detected methanotrophs from the groups Methylosinus and Methylococcus and methanogens from the groups Methanosarcinaceae, Methanococcaceae, and Methanobacteriaceae. 16S rDNA sequences amplified with the Methylosinus-specific primer were shown to have a high degree of identity with 16S rDNA sequences previously detected in acidic environments. However, no methanogen sequences were detected by the probes available in this study in the sections of the peat core (above 7 cm) where the majority of methanogenesis occurred, either because of low methanogen numbers or because of the presence of novel methanogen sequences.http://link.springer-ny.com/link/service/journals/00248/bibs/38n3p225.html</hea

DNA base composition of bacterial groups differentiated by a diagnostic scheme used for soil isolates

Abstract The first step in the systematic study of an unknown microorganism is to determine to which major groups of microorganisms it belongs. Over the past decades, bacterial taxonomy had traditionally relied on phenotypic analysis as the basis of classification although this approach was fraught with problems. Therefore, some simple diagnostic schemes based on phenotypic characters have been used to group the isolates roughly from natural habitats (Shewan et al. 1960; Ushikoshi 1974; Sato et al. 1987). These grouping schemes have provided valuable information about the natural distribution of bacteria.

Application of PCR: Organismal and Population Biology

sive analysis of gene structure from a limited number of species, primarily humans, mice, fruit flies, yeast, and the bacterium Escherichia coli. The powerful new molecular biological methods have also led to major discoveries in population biology and the study of organismal evolution. Among the many achievements are a better understanding of the evolutionary relationships among the major groups of microorganisms (Woese 1987) and the discovery that apes and humans had a common ancestor as recently as 5 million years ago (Wilson et al. 1989). Despite the profound nature of such discoveries, little data have been generated by molecular biological methods when the world's total biota is considered. Only a small number of individuals and species have been

Prevalence of microorganisms in field-sampled borers on sorghum, maize, and cowpea in Western Kenya

A survey carried out over Western Kenya in order to determine the prevalence of microorganisms in cereal stem borers and legume pod borer showed the presence of a large number of insect pathogens in the dead larvae. Larval cadavers were recovered from all sampling sites. Bacterial and fungal microorganisms were highly prevalent. Other major groups of microorganisms were also recovered, although at a low level. Viruses (polyhedral inclusion bodies and granulosis viruses) occurred at 2.7% at the Mbita Point Field Station, and 1.1% in the field. Mermithids and rhabditids occurred at 0.4% in the station and 0.6% in the field, whereas the protozoans (microsporidia and gregarines) were more prevalent in the station than in the farmers’ fields (9.4 and 1%, respectively). The spotted stalk borer, Chilo partellus was the most common borer sampled, but Busseola fusca and legume pod borer, Maruca testulalis were sampled in most sites too. Sesamia calamistis and Eldana saccharina were recorded at a low level, and C. orichalcoceliellus was recorded only at the Kenya coast.

Studies on lignin removal by soil perfusion technique

Studies were carried out using a soil perfusion apparatus for the removal of lignin from waste water. It was observed that when a medium (pH 7.0) with lignin having about 1200 color units was perfused through a soil column, perfusate contained only 250 to 300 color units after three days of perfusion and pH was reduced to less than 5.0 with 70 to 80% reduction in Total Organic Carbon (TOC). With a sterile soil column the color was not removed and there was no change in TOC content. When the medium was buffered at pH 7.0, there was no reduction in color units. When the pH of the perfusate reduced to less than 5.0, it was also observed that the nitrate content had increased considerably. These results indicated that due to microbial activity lignin molecules might have been biotransformed and adsorbed on the soil column at lower pH. The major group of microorganisms were also isolated from the soil and their significance is discussed in this paper.

Influence of Simulated Fall and Spring Conditions on the Soil System: III. Effect of Method of Simulating Spring Temperatures on Ammonification, Nitrification, and Microbial Populations

AbstractExperiments were carried out to determine (i) how different methods of simulating spring temperatures affect soil microbial activity, and (ii) the interactions between different types and amounts of added‐N and these temperature effects.In soil amended with mineral‐N, ammonification (change in NO3‐N + NH4‐N) was inversely proportional to the amount of added‐N when incubated at 8.5C, but ammonification was not affected by amount of N when incubated at fluctuating temperatures. When peptone‐N was added to soil, ammonification was unaffected by the method of simulating spring temperature conditions.In unamended soil and soil amended with 10 ppm NH4‐N, nitrification was greater at 8.5C than at square‐wave 14 to 3C. When peptone‐, NH4‐, or NO3‐N was added to soil, nitrification at 8.5C was generally equivalent to that at square‐wave 14 to 3C, but less than that at sine‐wave 14 to 3C. Where peptone‐N was added nitrification was &gt; NH4‐N added &gt; NO3‐N added.In unamended soil, fluctuating temperature cycles were deleterious to the three major groups of microorganisms but were particularly detrimental to the nonsporeforming, gramnegative bacteria. Square‐wave fluctuating temperature was more deleterious than sine‐wave; the constant temperature regime was not deleterious. The deleterious effect of fluctuating temperatures was partially alleviated by addition of 25 ppm NH4‐N.It was suggested that the protoplasmic materials released from the cells killed as a result of the fluctuating temperatures served as a ready source of N and energy substrate (much like the peptone amendment) for use by the surviving microbial populations.

Effects of captan on the non-parasitic microflora of apple leaves

The microflora of leaves from Worcester Pearmain apple trees sprayed with captan according to normal orchard practice, and from unsprayed trees, was examined by shaking, macerating and spore-fall techniques. Serial dilutions of macerates or wash liquids were incubated on selective media and the major groups of micro-organisms enumerated. Bacteria and yeasts were more numerous than moulds. Total numbers of yeasts and moulds were greatly reduced by captan but this effect was not long-lasting so that by the end of the season the numbers, and proportions of the major groups, on leaves from sprayed and unsprayed trees, were similar. The effect of captan sprayed in one season was not carried over to the next season. No conclusive data were obtained on the toxicity of captan to leaf bacteria. The implications of fungicide usage in relation to the balance of saprophytic and parasitic micro-organisms of the phylloplane are discussed.

Papers Presented at Symposium on Diarrheal Diseases Other Than Amebiasis Joint Meeting of The American Society of Tropical Medicine and Hygiene and The American Academy of Tropical Medicine Louisville, Kentucky November 12–14, 1953

The problem of acute diarrheal disease is closely analogous to that of the weather. We've learned how to live with weather. In many cases we have found ways of protecting ourselves against weather and we are still actively exploring other possibilities for modifying ourselves and our environment so that we can develop coexistence to a high degree. Similarly, diarrheal diseases are progressively better understood and consequently we are better protected than ever before. The group of papers is presented as one way of looking at the problem of those “diarrheal diseases other than amebiasis.” The papers themselves illustrate a stage in the acquisition of useful knowledge about particular disease agents. Two major groups of micro-organisms have been recognized as important agents for the production of these diseases in man: the genus “Shigella” and the genus “Salmonella,” respectively. In addition to these known parasites there is evidence which suggests to me that other bacteria and other viruses cause disease in man whose predominant symptom is diarrhea.