Agricultural Waste Annona squamosa L. Peel and Seed Extract: Biosynthesis of Hand Sanitizer Gel against Skin Pathogens

Alcohol-based hand sanitizers are being recommended as an infection prevention measure for COVID-19. Washing hands is a simple matter to eliminate and minimize germs on the hands with water and by adding certain ingredients, the use of hand sanitizer becomes must in recent circumstances. We have developed reliable and eco-friendly process for the synthesis of hand sanitizer gel that is a really useful tool in the fight against SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19). Considering scanty literature available on the use of custard apple peel and seed for preparation of hand sanitizer gel, present study was undertaken to evaluate effect of hand sanitizer from custard apple peel and seed extract. The antimicrobial activity of the formulated gel was tested against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis subsp. spizizenii, Salmonella typhimurinum and Shigella sonnei by The Quality Assurance and Testing Center 3 (QUATEST 3) in Ho Chi Minh city, Viet Nam.

Actividad biológica y composición química en extractos de Cucurbita ecuadorensis H.C. Cutler & Whitaker

Los metabolitos secundarios presentes en los extractos etanólicos y clorofórmicos de los frutos y hojas de Cucurbita ecuadorensis H.C. Cutler & Whitaker, una especie endémica de los bosques secos de la costa de Ecuador, fueron alcaloides, flavonoides, taninos, triterpenos, esteroles y cumarinas, mientras que las quinonas, antraquinonas y saponinas estuvieron ausentes. El mesocarpio del fruto de esta especie presentó contenidos de 9.19 ± 0.25 g de carbohidratos totales/ 100 g de peso seco, 14.90 ± 0.30 g de lípidos totales/ 100 g de peso seco y 3.39 ± 0.08 g de proteínas totales/ 100 g de peso seco, respectivamente. El mayor contenido fenólico fue para el extracto etanólico de los frutos con 20.82 ± 0.87 mg de GAE /g de extracto seco. El mayor contenido de flavonoides totales fue para el extracto etanólico de los frutos con 134.36 ± 0.34 mg de CE/ g de extracto seco. El extracto etanólico del fruto revelo la mayor capacidad antioxidante con IC50= 1.90 mg/mL. Todos los extractos evaluados de esta especie, no presentaron actividad antibacteriana contra Escherichia coli, Pseudomonas aeruginosa, Vibrio parahaemolyticus, Staphylococcus aureus, Bacillus subtilis subsp. spizizenii y Listeria monocytogenes. En base a estos resultados, los frutos de C. ecuadorensis se los puede considerar como un suplemento nutricional con un potencial antioxidante natural.

Enhanced Phytase Production by Bacillus subtilis subsp. subtilis in Solid State Fermentation and its Utility in Improving Food Nutrition

Background: Phytic acid acts as anti-nutritional factor in food and feed ingredients for monogastric animals as they lack phytases. Objective: Phytase production by Bacillus subtilis subsp. subtilis JJBS250 was studied in solid state fermentation and its applicability in dephytinization of food Methods: Bacterial culture was grown in solid state fermentation using wheat bran and various culture conditions were optimized using ‘One variable at a time’ (OVAT) approach. Effects of different substrates (wheat bran, wheat straw, sugarcane bagasse), incubation time (24, 48, 72 and 96 h), incubation temperatures (25, 30, 35 and 40 oC), pH (4.0, 5.0, 6.0, 7.0 and 8.0) and moisture content (1:1.5, 1:2.0, 1:2.5 and 1:3) were studied on phytase production. Bacterial phytase was used in dephytinization of food samples. Results: Optimization of phytase production was studied in solid state fermentation (SSF) using ‘One variable at a time’ (OVAT) approach. Bacillus subtilis subsp. subtilis JJBS250 grew well in various agroresidues in SSF and secreted high enzyme titres using wheat bran at 30 oC and pH 5.0 after incubation time of 48 h with substrate to moisture ratio of 1:3. Glucose and ammonium sulphate supplementation to wheat bran further enhanced phytase production in SSF. Optimization of phytase production resulted in 2.4-fold improvement in phytase production in solid state fermentation. The enzyme resulted in dephytinization of wheat and rice flours with concomitant release of inorganic phosphate, reducing sugar and soluble protein. Conclusion: Optimization resulted in 2.34-fold enhancement in phytase production by bacterial culture that showed dephytinization of food ingredients with concomitant release of nutritional components. Therefore, phytase of B. subtilis subsp. subtilis JJBS250 could find application in improving nutritional quality of food and feed of monogastric animals.

Self-healing bacterial cementitious concrete composites: development and performance evaluation

The principal objective of the research is to contribute towards attaining the goal of developing self-healing cementitious concrete composites by incorporating bacteria as healing agent. Since the root cause of the majority of structural failure is attributed to concrete cracking, there is a compelling economic incentive to develop a concrete that can treat and repair the damage all by itself. Even though some research has been carried out in this area, a major breakthrough in identifying the types of bacteria, modes to protect this bacteria from high pH concrete environment and nutrients for effective healing are yet to materialise. For the present study, three different bacteria namely, Sporosarcina ureae, Sporosarcina pasteurii and Bacillus subtilis subsp. spizizenii and two protective vehicles such as zeolite and pumice were selected to determine the best combination among them for self-healing. Normal and fibre reinforced mortar and engineered cementitious composite (ECC) specimens were employed for the study. In order to develop self-healing bacterial concrete based materials, it is crucial to understand whether the introduction of mineral producing bacteria and nutrients adversely affect the properties. Thus, various concentrations of bacteria and nutrients were tested to determine the best possible combinations without sacrificing concrete properies. Evaluation of healing effect was determined by comparing compressive strength, sorptivity and rapid chloride permeability (RCPT), four point bending and ultrasonic pulse velocity (UPV) properties of sound and damaged specimens at different ages. Healing associated with crack closure was visualised and analysed using scanning electronmicroscopy (SEM), Energy Dispersive Spectrum Energy (EDS) and X-ray diffraction (XRD) studies. Finally, an attempt was made to employ statistical models for parameter optimization of self-healing characteristics in terms of compressive strength, sorptivity, RCPT and UPV by design and analysis of experiments. Evaluation of results to determine self-healing efficiency indicated that a significant amount of self-healing was achieved by all three selected bacteria, out of which Sporosarcina pasteurii and Bacillus subtilis subsp. spizizenii found to be promising choices. Both zeolite and pumice turned out to be effective protective vehicles. Statistical modelling of the experiment proved to be the ideal choice for modelling self-healing characteristics.

Self-healing bacterial cementitious concrete composites: development and performance evaluation

The principal objective of the research is to contribute towards attaining the goal of developing self-healing cementitious concrete composites by incorporating bacteria as healing agent. Since the root cause of the majority of structural failure is attributed to concrete cracking, there is a compelling economic incentive to develop a concrete that can treat and repair the damage all by itself. Even though some research has been carried out in this area, a major breakthrough in identifying the types of bacteria, modes to protect this bacteria from high pH concrete environment and nutrients for effective healing are yet to materialise. For the present study, three different bacteria namely, Sporosarcina ureae, Sporosarcina pasteurii and Bacillus subtilis subsp. spizizenii and two protective vehicles such as zeolite and pumice were selected to determine the best combination among them for self-healing. Normal and fibre reinforced mortar and engineered cementitious composite (ECC) specimens were employed for the study. In order to develop self-healing bacterial concrete based materials, it is crucial to understand whether the introduction of mineral producing bacteria and nutrients adversely affect the properties. Thus, various concentrations of bacteria and nutrients were tested to determine the best possible combinations without sacrificing concrete properies. Evaluation of healing effect was determined by comparing compressive strength, sorptivity and rapid chloride permeability (RCPT), four point bending and ultrasonic pulse velocity (UPV) properties of sound and damaged specimens at different ages. Healing associated with crack closure was visualised and analysed using scanning electronmicroscopy (SEM), Energy Dispersive Spectrum Energy (EDS) and X-ray diffraction (XRD) studies. Finally, an attempt was made to employ statistical models for parameter optimization of self-healing characteristics in terms of compressive strength, sorptivity, RCPT and UPV by design and analysis of experiments. Evaluation of results to determine self-healing efficiency indicated that a significant amount of self-healing was achieved by all three selected bacteria, out of which Sporosarcina pasteurii and Bacillus subtilis subsp. spizizenii found to be promising choices. Both zeolite and pumice turned out to be effective protective vehicles. Statistical modelling of the experiment proved to be the ideal choice for modelling self-healing characteristics.

Synthesis, characterization and antimicrobial activity of copper(II) Schiff base adducts of some p-substituted aniline Schiff bases

The synthesis, characterization and antimicrobial activity of Cu(II) complexes of some p-substituted aniline Schiff base ligands have been carried out. The Schiff bases were obtained from salicylaldehyde and o-vanillin. The Cu(II) complexes have been characterized by elemental analysis, conductivity measurement, infrared and electronic spectral data. The complexes were obtained either as metal chelates [Cu(L)2] or Schiff base adducts (CuCl2.2LH).xH2O. The metal chelates were non-electrolytes while the Schiff base adducts exhibited 1:1 or 2:1 electrolytes in methanol. The Cu(II) complexes exhibited slight antimicrobial activity against Escherichia coli ATCC® 8739™*, Staphylococcus aureus subsp. aureus ATCC® 6538™*, Bacillus subtilis subsp. spizizenii ATCC® 6633™* and Candida albicans ATCC® 2091™*. The complexes exhibited significant antifungal activity. KEY WORDS: Metal Chelates, Schiff bases, Adducts, Cu(II) complexes, Salicylaldimines Bull. Chem. Soc. Ethiop. 2021, 35(1), 33-42. DOI: https://dx.doi.org/10.4314/bcse.v35i1.3

Draft Genome Sequence of the Type Strain Bacillus subtilis subsp. subtilis DSM10

ABSTRACT The Bacillus subtilis subsp. subtilis type strain DSM10 has been used as a reference in various studies. However, detailed information about the genome has not been available. Therefore, whole-genome sequencing was performed, and the sequence was compared with that of the related B. subtilis strain NCIB3610.