Pathogenic and Spoilage Causing Microorganisms Associated with Traditional Seafood Product Jaadi Manufactured in Southern and Western Coastal Belt of Sri Lanka

Aims: The objective of this study was to investigate on microbial related food safety issues and microorganisms associated with the production of Sri Lankan traditional seafood Jaadi. Place and Duration of Study: Food Technology Section, Industrial Technology Institute, Colombo, Sri Lanka, between December 2013 to April 2016. Methodology: Seven Jaadi processing centers along the Southern and Western coastal belt of Sri Lanka were evaluated for its compliance to food safety, in terms of environment, processing techniques, hygiene and sanitation, physiochemical and microbiological quality of the final product. Samples drawn from all sites were analyzed for its water activity, salt content, pH and microbiological quality. Microorganisms associated with Jaadi production were isolated in selective media, followed by phenotypical, biochemical and molecular biological characterization. Results: The pH, water activity and salt content of Jaadi samples ranged between 3.60-5.85, 0.73-0.82 and 24.82-40.47%, respectively. Thirteen bacterial strains and one fungal strain detected were strains found to be responsible for human pathogenesis and food spoilage. These include, Bacillus cereus strain I (MN726935.1), Bacillus cereus strain II (MN901259.1), Bacillus haikouensis strain I (MN901262.1), Bacillus haikouensis strain II (MN726976.1), Bacillus licheniformis (MN726987.1), Acinetobacter baumannii (MN901499.1), Bacillus pumilus strain I (MN901264.1), Bacillus pumilus strain II (MN901263.1), Bacillus paralicheniformis (MN901167.1), Bacillus thuringiensis strain I (MN901165.1), Bacillus thuringiensis strain II (MN901257.1), Bacillus cereus (MN901161.1), Staphylococcus saprophyticus (MN901156.1) and Trichoderma longibrachiatum (MN907169.1). Presence of such organisms clearly proclaims the poor hygienic practices and risks related to food safety in this traditional processing technology. Conclusion: Jaadi processing facilities of Southern and Western coastal belt of Sri Lanka needs scientific and technical knowledge to upgrade their processing in order to assure food safety and product quality.

Genomic exploration of Bacillus thuringiensis MORWBS1.1 - candidate biocontrol agent, predicts genes for biosynthesis of zwittermicin, 4,5-DOPA dioxygenase extradiol, and quercetin 2,3-dioxygenase

Many strains from the Bacillus thuringiensis spp. are known for their genomic robustness and antimicrobial potentials. As a result, the quest for their biotechnological applications especially in the agroindustry (e.g. as biopesticides) has increased over the years. This study documents the genome sequencing and probing of a Fusarium antagonist (B. thuringiensis strain - MORWBS1.1) with possible biopesticidal metabolite producing capacity from South Africa. Based on in vitro evaluation and in silico antiSMASH investigation, B. thuringiensis strain - MORWBS1.1 exhibited distinctive genomic properties that could be further exploited.

A novel anti-dipteran Bacillus thuringiensis strain: Unusual Cry toxin genes in a highly dynamic plasmid environment

Bacillus thuringiensis emerged as a major bioinsecticide on the global market. It offers a valuable alternative to chemical products classically utilized to control pest insects. Despite the efficiency of several strains and products available on the market, the scientific community is always on the lookout for novel toxins that can replace or supplement the existing products. In this study, H3, a novel B. thuringiensis strain showing mosquitocidal activity, was isolated from Lebanese soil and characterized at an in vivo, genomic and proteomic levels. H3 parasporal crystal is toxic on its own but displays an unusual killing profile with a higher LC50 than the reference B. thuringiensis serovar israelensis crystal proteins. In addition, H3 has a different toxicity order: it is more toxic to Aedes albopictus and Anopheles gambiae than to Culex pipiens. Whole genome sequencing and crystal analysis revealed that H3 can produce eleven novel Cry proteins, eight of which are assembled in genes with an orf1-gap-orf2 organization, where orf2 is a potential Cry4-type crystallization domain. Moreover, pH3-180, the toxin-carrying plasmid, holds a wide repertoire of mobile genetic elements that amount to ca. 22% of its size., including novel insertion sequences and class II transposable elements Two other large plasmids present in H3 carry genetic determinants for the production of many interesting molecules - such as chitinase, cellulase and bacitracin - that may add up to H3 bioactive properties. This study therefore reports a novel mosquitocidal Bacillus thuringiensis strain with unusual Cry toxin genes in a rich mobile DNA environment. IMPORTANCE Bacillus thuringiensis, a soil entomopathogenic bacteria, is at the base of many sustainable eco-friendly bio-insecticides. Hence stems the need to continually characterize insecticidal toxins. H3 is an anti-dipteran B. thuringiensis strain, isolated from Lebanese soil, whose parasporal crystal contains eleven novel Cry toxins and no Cyt toxins. In addition to its individual activity, H3 showed potential as a co-formulant with classic commercialized B. thuringiensis products, to delay the emergence of resistance and to shorten the time required for killing. On a genomic level, H3 holds three large plasmids, one of which carries the toxin-coding genes, with four occurrences of the distinct orf1-gap-orf2 organization. Moreover, this plasmid is extremely rich in mobile genetic elements, unlike its two co-residents. This highlights the important underlying evolutionary traits between toxin-carrying plasmids and the adaptation of a B. thuringiensis strain to its environment and insect host spectrum.