Microbiome perspective: multisectorial exploitations of chitinases

Chitinases are cosmopolitan lytic enzymes secreted by microbiomes that fall under the domain of fungi, yeasts, bacteria and plants. Most fungal plant pathogens, human infectious agents and post-harvest damage caused by pathogens have been a serious threat to the economy and human health. Like fungi, crabs, insects, lobsters, shrimps, and invertebrates all have a hard disintegrating, flexible polymer called chitin that forms the exterior skeleton. It poses a wide-range of environmental problem and a major threat to humans, plants and animals. According to functional genomic research, there is a large diversity of chitinases-producing fungi in nature. They have adapted to a wide range of habitats on Earth including plants, animals and manmade natural and artificial habitats. Chitinases, both native and genetically modified, have been produced and expressed in an expression system such as Escherichia coli or Pichia pastoris through recombinant DNA technology. This versatile recombinant chitinases can be used for long-term growth and productivity. As a whole, chitinases have a wide range of applications in agriculture, horticulture , plant health, and bio-control of pests, and even some fuel processing, genetically engineered molecule-based therapies, polysaccharide hydrolysis, biomedicine, pathogenic/virulence agents, antifungal agents, and as a drug delivery system.Peer reviewe

Development of a recombinase polymerase based isothermal amplification combined with lateral flow assay (HLB-RPA-LFA) for rapid detection of "Candidatus Liberibacter asiaticus".

Huanglongbing (HLB) or citrus greening is highly destructive disease that is affecting the citrus industry worldwide and it has killed millions of citrus plants globally. HLB is caused by the phloem limited, Gram negative, non-culturable, alpha-proteobacterium, 'Candidatus Liberibacter asiaticus'. Currently, polymerase chain reaction (PCR) and real time PCR have been the gold standard techniques used for detection of 'Ca. L. asiaticus'. These diagnostic methods are expensive, require well equipped laboratories, not user-friendly and not suitable for on-site detection of the pathogen. In this study, a sensitive, reliable, quick and low cost recombinase polymerase based isothermal amplification combined with lateral flow assay (HLB-RPA-LFA) technique has been developed as a diagnostic tool for detection of 'Ca. L. asiaticus'. The assay was standardized by designing the specific primer pair and probe based on the conserved 16S rRNA gene of 'Ca. L. asiaticus'. The assay was optimized for temperature and reaction time by using purified DNA and crude plant extracts and the best HLB-RPA-LFA was achieved at the isothermal temperature of 38°C for 20 to 30 min. The efficacy and sensitivity of the assay was carried out by using field grown, HLB-infected, HLB-doubtful and healthy citrus cultivars including mandarin, sweet orange cv. mosambi, and acid lime. The HLB-RPA-LFA did not show cross-reactivity with other citrus pathogens and is simple, cost-effective, rapid, user-friendly and sensitive. Thus, the HLB-RPA-LFA method has great potential to provide an improved diagnostic tool for detection of 'Ca. L. asiaticus' for the farmers, nurserymen, disease surveyors, mobile plant pathology laboratories, bud-wood certification and quarantine programs