Metagenomic tracking of microbial consortia of cassava flakes (garri)

The affirmation of several cross-sectional studies on the vulnerability of cassava flakes commonly called 'garri' to microbial attack has long been documented. However, longitudinal data on metagenomic tracking of microbial consortia of this important staple food are scarce. Hence, this study was aimed at tracking the microbial consortia of garri. A total of eight samples (four each from both Nigeria and Republic of Benin markets) were randomly collected aseptically using pre-sterilized aluminum pans and processed through a metagenomic approach, while both the chemical and proximate components of garri were assessed following standard techniques. The analysis of the taxonomic consortia of garri reveals the predomination of bacteria (99.82 and 99.81% for samples from Nigeria and Republic of Benin, respectively) while the remaining sequences matched with the Archae (0.07%), fungi (0.09%) and protozoa (0.09%). A large proportion of the sequences were unclassified at the phylum level (approximately 84.10 and 86.2% for Nigerian and Beninese samples, respectively). The reads of cassava flakes metagenome of both Nigeria and Republic of Benin exhibited analogous level of average GC content with sequence count of between 187773-213444 for samples from Nigeria and 157784-198763 for samples from Republic of Benin. The functional characteristics of the inhabiting metagenomes were found containing the genes encoding for adhesins, bacteriocins, resistance to antibiotics, toxic chemicals as well as toxins and superantigens. Both the chemical and the proximate compositions of the examined garri samples, though exhibited significant disparity, but without any apparent variation in the patterns of metagenomic data. Our findings however revealed bacteria as the major contaminants of these cassava food products. Keywords; Metagenomics, Microorganisms, Cassava flakes (garri), Proximate composition

Type VI secretion system mutations reduced competitive fitness of classical Vibrio cholerae biotype

The gram-negative bacterium Vibrio cholerae is the causative agent of the diarrhoeal disease cholera and is responsible for seven recorded pandemics. Several factors are postulated to have led to the decline of 6th pandemic classical strains and the rise of El Tor biotype V. cholerae, establishing the current 7th pandemic. We investigated the ability of classical V. cholerae of the 2nd and 6th pandemics to engage their type six secretion system (T6SS) in microbial competition against non-pandemic and 7th pandemic strains. We report that classical V. cholerae underwent sequential mutations in T6SS genetic determinants that initially exposed 2nd pandemic strains to microbial attack by non-pandemic strains and subsequently caused 6th pandemic strains to become vulnerable to El Tor biotype V. cholerae intraspecific competition. The chronology of these T6SS-debilitating mutations agrees with the decline of 6th pandemic classical strains and the emergence of 7th pandemic El Tor V. cholerae.

Spatial Distribution and Isolation of Microbiota Associated with Spoilage of Tomatoes Sold in Selected Markets in Nasarawa State, Nigeria

Tomato (Lycopersicum spp) is widely consumed universally because of its high nutritive value, but suffers great post-harvest losses due to microbial attack. This work was carried out to investigate the causative agents of tomato spoilage and the spatial distribution of such causative agents in some selected major markets in Nasarawa State, Nigeria. Sixty tomato fruits from each of the four selected markets (total of 240 fruits) were investigated for the microorganisms responsible for tomato fruit spoilage. Eleven microorganisms, comprising of five bacterial species and six fungal species were isolated from the spoilt tomatoes. The bacterial isolates included Micrococcus varians, Lactobacillus fermenti, Escherichia coli, Salmonella sp and Klebsiella sp. The isolated fungi included Rhizopus stolonifer, Fusarium oxysporium, Aspergillus flavus, Geotrichum candidum, Mucor mucedo, and Candida tropicalis. They were all positive for the pathogenicity test. The isolated organisms were heterogeneously distributed with remarkable levels of severity across the study area. The bacterial load ranged between 2.09 X 109 and 2.56 X 109, while the fungal load ranged between 2.72 X109 and 3.97 X 10 9. The occurrence and magnitude of the spoilage, and hence economic loss due to microbial attack could be attributable to the biologic, ecologic and environmental factors of the study area. Recommendations were, therefore, made for improved personal and environmental hygiene, good agricultural practice and proper treatment of tomato fruits before consumption to avert the imminent health consequences due to the spoilage microorganisms.

Cold Chain Supply in Dairy Industry in India

The study provides an overall idea about the development of cold chain in the dairy industry as well as the necessity of having cold chain management in the dairy sector. Cold Chain involvement has been a huge contribution to the dairy sector as it has helped the sector to flourish more as well as to unfold to its maximum potential. Cold chain statistics provides the information to know about the present status of cold chain in the nation. Cold chain in the country is still under development and hasn’t been used to its utmost advantages and uses which will be explored in the forthcoming years. The reason or challenges encountered by the cold chain while its practice are the major drawback for the lack of cold chain application in the country which also have been tapped upon in the study. The present scenario of the dairy sector with the application of cold chain helped to minimise the losses of the dairy sector by a huge margin. The application of cold chain in dairy sector is practised in the storage and transportation of milk and its value based products hence government also provides schemes and initiatives for the usage of cold chain supply s it ensures zero wastage, affordable product, accessible product, healthy and nutritious products. The cold chain supply has essential steps of storage and transportation which have been explained in the study through the considerations of the appropriate design of cold storage based upon the product to be stored. There are various types of cold storage which must be taken into consideration while designing of cold storage. The cold chain supply of milk and its value added products varies from product to product and it must be ensured for preservation of quality and its shelf life throughout the cold chain supply by inhibiting the product from microbial attack hence the maintenance of the ambient temperature is absolutely necessary throughout the cold chain which is done by various practices in the dairy sector as mentioned in the study. The study in brief provides with the overview of the cold chain supply in dairy industry along with its challenges, applications, present scenario, statistics and assessment of the dairy sector for milk and its value added products from farm to consumers ensuring that there is no breakage of the cold chain until the product reaches the consumers.

Biodiversity and Phylogenetic Relationship of Total Hydrocarbon Degrading Genes in Selected Bacteria Species

Hydrocarbons which forms the bulk of soil and water pollutants in the Niger Delta region of Nigeria differs in their susceptibility to microbial attack and degradation. Considering the importance of hydrocarbons in the economy of any nation, a complete knowledge of the hydrocarbons degrading capabilities of associated microbial species becomes increasingly important and indispensable. The research was aimed at assessing the biodiversity and phylogenetic relationship of hydrocarbon degrading genes in selected bacteria species. Sequences of nucleotides and amino acids of hydrocarbons degrading genes in 12 species of bacteria such as Pseudomonas aeruginosa I & II, P. stutgeni, Thalassosqir spp. I & II, Alcavorox spp., Arthrobacter spp., Martellela spp., P. taenensis, Aneuribacillus species, Rhodococcus spp. and Uncultured bacteria, were retrieved from the National Center for Biotechnology Information (NCBI) and analysed for their variability in physicochemical properties, percentage identity and similarity, G-C content, secondary and tertiary structures, their biodiversity and their phylogenetic relationship using MEGA 6 soft-wares, GOR IV, Phyre, Genscan and SIB Protparam. The analysis showed great genetic diversity and polymorphism in the hydrocarbon degrading genes present in the bacteria species. The phylogenetic tree showed that the genes in most species had undergone mutation. Martella spp had the highest probability or chance of mutating with E-value of 7e-129. Only two of the bacteria species had low instability index indicating that majority of the bacteria species contains or possessed the unstable nature of the hydrocarbon degrading genes. The biodiversity of bacterial species and their genetic distance was ascertained.

Formulation and Evaluation of Triclosan Dispersible Tablets for Oral Hygiene

In human anatomy mouth is the earliest segment of alimentary canal which receives food and fabricates saliva, and is one of the foundation for bacterial development due to accretion of sugars form food chunks. There have been more than 300 kinds of bacteria set up in the mouth. The purpose of the present study is to investigate the number of microbes’ grown-up at different timings of the day by collecting the samples from individual volunteer oral cavities and counting the colonies; the utmost count was noted as in the range of 190-200 in the evening samples. The same samples were used to calculate minimum inhibitory concentration of Triclosan, the antibiotic formulated for oral hygiene. Triclosan dilutions were prepared and analyzed for the inhibition zones, it resulted that 300mg of the drug have shown satisfactory results. Triclosan was formulated into a dispersible tablet to enable dispersion of tablet into water for rinsing the oral cavity to remove the contaminants. The Dispersion time of the tablet was within the range of 43.66-111.33 second and it was observed that formulation was acceptable with reasonable limits of standard required for dispersible tablets. Addition of superdisintegrant enhanced the dispersion time which facilitates easy mixing of tablet in water. It concludes that superdisintegrant addition technique is a useful method for preparing dispersible tablets by wet granulation method, and Triclosan dispersible tablet further reduces the microbial attack on tooth by rinsing each time after meals, upon doing so on long term basis the dental decays will probably be eradicated.

A Review of Intermediate Pyrolysis as a Technology of Biomass Conversion for Coproduction of Biooil and Adsorption Biochar

The agenda to utilize and efficiently convert biomass has been raised to alleviate environmental problems and pressure on the reliance on fossil fuel. Intermediate pyrolysis has the ability to treat different biomasses and coproduction of biooil and adsorption biochar. This review article aims to evaluate the appropriateness of intermediate pyrolysis for the coproduction of biooil and adsorption biochar. It was observed that coproduced biooil is of high quality, stable, and miscible that can be used directly to existing engines or be easily blended. The biochar coproduced is good for adsorption but is not stable for microbial attack and hence unsuitable in soil treatment but for hydrometallurgy. Since the process is capable of treating waste biomass, it is an opportunity for further investigations in areas where wastes are plenty and less utilized. To increase the effectiveness of this technology for coproduction, optimizing parameters, design of efficient reactors, and use of catalyst must be worked upon.

RhoGTPases and inflammasomes: Guardians of effector-triggered immunity

Pathogens have evolved smart strategies to invade hosts and hijack their immune responses. One such strategy is the targeting of the host RhoGTPases by toxins or virulence factors to hijack the cytoskeleton dynamic and immune processes. In response to this microbial attack, the host has evolved an elegant strategy to monitor the function of virulence factors and toxins by sensing the abnormal activity of RhoGTPases. This innate immune strategy of sensing bacterial effector targeting RhoGTPase appears to be a bona fide example of effector-triggered immunity (ETI). Here, we review recently discovered mechanisms by which the host can sense the activity of these toxins through NOD and NOD-like receptors (NLRs).

Fungal communities in the biofilms colonizing the basalt sculptures of the Leizhou Stone Dogs and assessment of a conservation measure

The Leizhou Peninsula in China is very famous for its unique folk art creation, especially for the stonework, like the basalt sculptures of the Leizhou Stone Dogs, which have a history of more than two thousand years. Since these sculptures are usually exposed outdoors, many of them are suffering from severe damage by lichen and fungi. To protect them from microbial attack, we determined fungal communities in the biofilms colonizing the stone dogs and explored an effective conservation measure. Specifically, the micromorphology analysis of the biofilms on the stone dogs was performed through both on-site and laboratory-based microscopies in order to provide an overview of the fungal community structure. High-throughput sequencing analysis revealed that the predominant fungi in the biofilms belong to the following genera Caloplaca, Chaetomium, Clitopilus, Acanthostigma, Tolypocladium, Aspergillus, and Toxicocladosporium. The energy dispersive X-ray spectrometry (EDS) showed that the basalt is mainly composed of silica (53% by weight), followed by Al2O3 (14.4%), Fe2O3 (10.1%), CaO (8.4%), and MgO (7.4%) that are oxides susceptible to corrosion of biogenic acids. The EDS analysis of the hyphae provided the direct evidence on the leaching of the minerals of the sculptures. To control microbial attack, three kinds of antimicrobial agents were tested for 2 years. As a result, the mixture of biocide and water repellent showed the best effectiveness. Our findings provide an overview of fungi diversity in the biofilms on the stone dogs and help the investigation of fungi-induced biodeterioration and the exploration of specific conservation measure.

The combined effect of coating treatments to nisin, nano-silica, and chitosan on oxidation processes of stored button mushrooms at 4 °C

Agaricus bisporus is an edible fungus with a limited shelf life due to high moisture loss, browning, respiration, self-dissolve, lack of physical protection, rotting, and microbial attack. Mushrooms have been coated with nisin, nano-silica, and chitosan films in order to extend the shelf life, preserve quality and oxidation activities. The results showed that treating the mushrooms with chitosan and nano-silica (CH-AN-SILICA) increased superoxide dismutase activity (SOD—6.53 U kg−1), total phenolic content (TPC—0.39 g kg−1), and malondialdehyde content (MDA—1.63 µmol kg−1). CH-AN-SILICA treatment exhibited the highest scavenging against 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals. While, CH-AN-SILICA with the addition of nisin as an antimicrobial agent preserved almost the reactive oxygen species such as hydroxyl radicals (OH—0.33 µmol g−1), superoxide anion (O2•−—0.271 mmol s−1 kg−1), and hydrogen peroxide (H2O2—21.54 µmol g−1). Besides, both CH-AN-SILICA and CH-AN-SILICA/N enhanced the catalase (CAT) activity and reduced the respiration rate. The results indicated that the combination of nisin, nano-silica, and chitosan coating films was effective in providing a longer storage life with acceptable quality in mushrooms.