Effect of Endophytic Serratia marcescens Isolated from Bryophyllum pinnatum against Clinical Bacterial Isolates

The world's health is being threatened by antimicrobial resistance (AMR). According to the World Health Organization, it is one of the top ten worldwide public health problems facing humanity. Serratia marcescens is an opportunistic pathogen that can be isolated from soil, plants, water, and air. Additionally, Serratia species offer a valuable supply of secondary metabolites that are comparatively underutilised and may have anti-MDR pathogenic properties. The present research aimed to determine the antibacterial potential of Serratia marcescens isolated from the leaves of Bryophyllum pinnatum against clinical bacterial isolates. The leaves of Bryophyllum pinnatum were collected, surface sterilised, cultured at 37 °C for 24 hours and identified utilising viteks 2 automated techniques and molecular methods. The crude metabolites extract of Serratia marcescens were extracted and utilised for antibacterial susceptibility testing using agar healthy diffusion methods. The data were measured in the diameter zone of inhibition. This study revealed six endophytic bacteria were isolated from Bryophyllum pinnatum following standard microbiological culture methods. The endophytic bacteria isolate tag L03 was found to be Gram-Negative Rod. The isolate was tentatively identified as Serratia ficaria and molecularly identified as Serratia marcescens. The metabolites of Serratia marcescens endophytes revealed a significant antibacterial activity on Klebsiella pneumoniae with a diameter zone of inhibition of 17.7 mm at 100% concentration, followed by Staphylococcus sciuri with a 12.7 mm diameter zone of inhibition. These results suggested that endophytic bacteria Serratia marcescens were isolated from the leaves of Bryophyllum pinnatum and had shown potent antibacterial activity that could be employed to create new antibacterial agents

Antibacterial Activity of Endophytic Bacteria from Stem Bark of Dialium guineense (Wild).

Dialium guineense or African black velvet tamarind, is a common tree in West Africa whose parts have been established for its antimicrobial and therapeutic properties. In this study, the stem bark of the plant was accessed for endophytic bacteria and their activity against common clinical isolates were evaluated. Isolation of bacteria endophytes from the stem bark of the plant was achieved by surface sterilization using 70% ethanol and 2% sodium hypochlorite before aseptically cutting into small sizes of about 3.5 - 4.0 mm, plated on nutrient agar and then incubated for 24 hours. Pure isolates of the endophytes were obtained and identified macroscopically and molecularly by depositing 16SrRNA sequences of all the isolates on NCBI website. The endophytic bacteria isolates belong to the genera Pseudomonas, Halopseudomonas, Burkholderia, Streptococcus and Bacillus. Antibacterial activity carried out with the crude extracts of all endophytic bacteria isolates revealed that the bacteria endophyte mSB2 of the genera Halospeudomonas, had the most clearer zones and diameter of inhibition against all test isolates with zones ranging from 9.0 ± 0.35 mm to 35 ± 0.5 mm; hence, the extract from mSB2 was most active and posed effective antibacterial activities. This study established a fact that Dialium guineesnse harbors bacteria endophytes with active metabolites against common disease-causing organisms. Keywords: Dialium guineense, Endophytic bacteria, Stem bark, Antibacterial activities, Metabolites. DOI: 10.7176/JNSR/14-12-04 Publication date:September 30th 2023

In silico evaluation of the antimicrobial potentials of soluble bioactive compounds derived from Weissella ciberia metabolites.

Weissella species are a group of lactic acid bacteria gaining rapid popularity as a result of discoveries centered on their biotechnological properties. In this study, an in silico approach was imbibed to investigate the antimicrobial potentials of metabolites of Weissella ciberia. Soluble compounds of W. ciberia were subjected to High Performance Liquid Chromatographic (HPLC) analysis and the inherent metabolites were identified. In order to evaluate their antimicrobial potentials against Escherichia coli and Shigella flexneri, the identified metabolites of W. ciberia were further subjected to geometry optimization of compound structures, ligand/receptor preparation, docking calculations and docking simulations. The HPLC identified metabolites from W. ciberia were atropoine, gallic acid, naringinin, caffeine, maleic acid, saponin and glutathione. The results of the in silico analysis showed binding affinities of the metabolites against the target microorganisms at a range of ˗4.6 to 10.7 Kcal/mol. Among metabolites, the highest binding affinity was observed in saponin against E. coli and S. flexneri at scores of ˗9.7 Kcal/mol and ˗10 Kcal/mol respectively. Binding affinities against E. coli and S. flexneri were also observed in naringinin at binding scores of ˗7.8 Kcal/mol and ˗8.5 Kcal/mol respectively. The scores obtained in this study predicts strong antimicrobial potentials that were comparable to those of conventional antibiotics such as ciprofloxacin and meropenem. Hence, the antimicrobial activities of metabolites of W. ciberia could be harnessed further for their potential in drug sensitivity against multiple-drug resistant pathogenic microbes. KEYWORDS: Bioactive, metabolites, fermentate, in silico and binding affinity. DOI: 10.7176/JNSR/14-12-06 Publication date:October 30th 202

Biosensors: A Fast-Growing Technology for Pathogen Detection in Agriculture and Food Sector

Agriculture and food have a greater role to play in order to achieve sustainable development goals. Therefore, there is a need to put an end to the effect of pathogens on food quality and safety. Pathogens have been recognized as one of the major factors causing a reduction in profitable food production. The conventional methods of detecting pathogens are time-consuming and expensive for the farmers in rural areas. In view of this, this chapter reviews the biosensors that have been developed for the detection of biological hazards in food and agricultural sectors. This chapter also lays emphasis on the impact of nanotechnology on building a fast, reliable, more sensitive, accessible, user-friendly and easily adaptable technology for illiterate farmers in the rural communities. On the whole, we have addressed the past and most recent biosensors that could ensure the quick delivery of vision 2030 which aims to end hunger and poverty

Influence of chitosan edible coating on postharvest qualities of Capsicum annum L. during storage in evaporative cooling system

Chitosan is a biopolymer edible coating which can act as physical barrierwhen coated on fruits and efficiently alter their internal atmosphere and delay the ripening process. This study evaluates the usage of chitosan (CH) as edible coating to extend the shelf life of green bell pepper. Physiochemical and microbial analysis of the green bell pepper was conducted during evaporative coolant structure storage (ECS). The effect of chitosan coating on green bell pepper significantly delayed a loss in firmness, weight loss, and vitamin C content and inhibited the growth of heterotrophic bacteria, mesophilic bacteria, yeast and mould during the five weeks of storage. On the whole, this study established that edible coating from chitosan could form a natural and permanent replacement to the chemically preservatives used for postharvest management of green bell pepper

Effect of rhamnolipid-Aloe vera gel edible coating on post-harvest control of rot and quality parameters of ‘Agege Sweet’ orange

A local cultivar of sweet orange namely ‘Agege sweet’ constitutes a larger percentage among many citrus varieties planted in Nigeria, but there is a major setback in terms of extending its post-harvest shelf life. This work was designed to assess the effectiveness of a rhamnolipid coating to preserve the quality attributes of Agege sweet orange fruit during 8 wk ambient storage compared with that of Aloe vera gel. Petri plates were supplied with different treatments (volume per volume, v/v) of Aloe vera gel (0%, 0.5%, 1.0%, 1.5%, 2.0%, 2.5%) or rhamnolipid (0%, 0.25%, 0.5%, 1.0%, 1.5 %, 2.0%) and oranges were inoculated with a spore suspension of P. digitatum NSP01 spores. The solutions of rhamnolipid (2%) and Aloe vera gel (2%) were evaluated for their biocontrol activity on P. digitatum NSP01. The fruits were stored for 8 wk at 25ºC. The lesion area, firmness, and chemical composition were assessed. The oranges coated with Aloe vera gel and rhamnolipid significantly (p < 0.05) prevented loss in firmness, total soluble solids and titratable acidity and reduced the decay caused by P. digitatum NSP01. Therefore, the newly formulated rhamnolipid-Aloe vera edible coating could serve as a permanent substitute for chemical fungicides used in the management of diseases and pests affecting agricultural productivity

ENVIRONMENTAL INFLUENCE OF CULTURALMEDIUM ON BIOHERBICIDAL ACTIVITIES OFPSEUDOMONAS AERUGINOSAC1501ON MONO AND DICO WEEDS

Microbe producing natural herbicides are alternatives to the chemical herbicidal formulations.The effect of minerals and carbon sources were screened to select the best when combined and whenapply singly during submerged fermentation. The effect of their phytotoxic metabolites was tested onChromolaena odorata and Echinochola crus-galli.It was observed that the best combination between all the mineral was found in the combinationcontaining manganese, zinc, bromine and iron. It gave the highest bio-herbicidal activities on thetested weeds when compared with the basal medium without any mineral amendment (P≤0.05).The best carbon source screened was glucose while the best mineral screened was iron in term ofshowing activities on the tested weeds (P≤0.05)

Prolonging the shelf life of ‘Agege Sweet’ orange with chitosan–rhamnolipid coating

This study evaluates the single and combined usage of chitosan (2% w/v) and rhamnolipid (2% w/v) as edible coatings to extend the shelf life of sweet oranges stored at 25 °C for 8 weeks. Physiochemical, microbial and sensory analysis of the oranges was conducted during ambient storage. The combined treatment of chitosan and rhamnolipid coating on oranges significantly delayed a loss in chlorophyll quality, malondialdehyde, weight loss, soluble solids content, titratable acidity, vitamin C content and delayed the loss of firmness during the 8 weeks of storage. The combined chitosan–rhamnolipid coating significantly increased the activities of superoxide dismutase, catalase, and peroxidase, as well as inhibited the generation of superoxide free radicals and the growth of mesophilic bacteria, yeast and mould

Silver nanoparticle synthesis by Acalypha wilkesiana extract: phytochemical screening, characterization, influence of operational parameters, and preliminary antibacterial testing

© 2019, The Author(s). Introduction: The application of skin bleaching products to inhibit melanogenesis is a common practice within the African diaspora. Despite the adverse health effects of skin bleaching, rigorous studies investigating skin bleaching behavior among these populations in the United States are limited. In our P30 pilot study, we explored predictors of skin bleaching practice intensity among African and Afro-Caribbean women. Methods: In collaboration with our Community Engagement Core, we conducted a cross-sectional study to investigate the relationship between demographic and psychosocial predictors and skin-bleaching-related practice patterns among African and Afro-Caribbean women in New York City. Results: Among the 76 participants recruited, the median age at the initiation of skin bleaching was 19.5 (16–25) years, yielding a median duration of 13.5 (6–23) years. Although pregnant women were not actively recruited for the study, 13.2% (n = 10) of the participants used skin bleaching products while pregnant or possibly breastfeeding. Nativeness and education were associated with various components of skin bleaching practice intensity, including duration of skin bleaching, daily use of products, and bleaching of the entire body. Participants’ perceived skin-color-related quality of life was not associated with skin bleaching practice intensity. Conclusion: Skin bleaching is a habitual practice that likely requires culturally sensitive interventions to promote behavioral change. The existence of prenatal and postnatal exposure to mercury, hydroquinone, and other potentially harmful chemicals in skin bleaching products highlights an urgent need to explore the adverse effects of skin bleaching practices on birth outcomes and the growth and neurodevelopment of young babies