Morphological and Histological Observation of Embryogenic Calli Derived from Immature Embryo of BRRI Dhan28 (Oryza sativa L.) Variety

Somatic embryogenesis is the most common method for regeneration in rice. In vitrostudies of indica rice (Oryza sativa L.) variety BRRI dhan28 was used for obtainingembryogenic calli from immature embryo culture on Murashige & Skoog mediumsupplemented with 2.5 mg/l dichlorophenoxyacetic acid (2,4-D) and 0.5 mg/lnaphthaleneacetic acid (NAA) showed the highest percentage (91%) of callus induction. Inthis combination 80% embryogenic calli were formed uneven with a crisp texture, loosestructure and salient multicellular structures on the surface while non embryogenic calliwere compact with a smooth surface. Under microscopic observation, embryogenic cells weresmaller, globular and abundant in cytoplasm with one or two big nuclei. Non embryogeniccells were little cytoplasm and few large vacuoles with no or only a small nucleus and wideintercellular spaces. Non embryogenic cells had a very low cell division capability whileembryogenic cells had a high capability for cell division and continued to divide andproduced somatic pro-embryos with a well–defined protodermis which could developfurther through the typical globular, heart, torpedo and cotyledonary stages. Only 80% ofembryogenic cells were induced high differentiation rate and developed 65 globular, 52heart-shape, 43 torpedo and 37 cotyledonary embryos of embryogenic cells after 30 to 45 daysof induction

Establishment of an Efficient Protocol for in Vitro Callus Induction and Regeneration System Using Mature Embryo in Elite Rice (Oryza sativa L.) Cultivars

The present investigation was undertaken to determine a suitable media compositions for callus induction and plant regeneration of rice (Oryza sativa L.) through somatic embryogenesis. Murashige and Skoog (MS) media composition and phytohormones (i.e. auxin; 2, 4-D, IAA, IBA and cytokinin; BAP, KIN) were tested for high callus induction and plant regeneration. Mature seeds of six rice cultivars namely BRRI dhan28, BRRI dhan29, BRRI dhan30, BRRI dhan34, BRRI dhan56 and BRRI dhan57 were used for the experimentation. 2.0 mg/l of 2,4-D + 0.5 mg/l of NAA were found suitable inducing high amount of calli and 2.0 mg/l of BAP+ 1.0 mg/l of NAA + 1.5 mg/l of KIN were found most effective for plant regeneration. Among cultivars for callus induction, BRRI dhan29 shows the highest percentage and BRRI dhan30 less and remaining cultivars (BRRI dha28, BRRI dhan34, BRRI dhan56 and BRRI dhan57) show moderate results in the experiments. Among cultivars for regeneration, BRRI dhan29 shows the highest percentage and BRRI dhan30 less and remaining cultivars (BRRI dha28, BRRI dhan34, BRRI dhan56 and BRRI dhan57) show moderate results. The investigation will provide valuable information for Agrobacterium mediated genetic transformation

Molecular Detection and Biological Control of Human Hair Dandruff Causing Microorganism Staphylococcus aureus

Human hair dandruff (HHD) is a common unwanted scalp disorder that is prevalent to most human populations all over the world. This study was designed to isolate and characterize pathogens that are responsible for HHD as well as the evaluation of their biological control technique. Isolated bacteria were characterized by different biochemical tests and molecular identification methods. Here, disc diffusion methods were used to determine antibiotic and antibacterial activity against isolated bacteria. The isolated bacterial colonies were found to be Gram-positive, small, round-shaped, and purple. PCR amplification was done using 27F and 1492R primer pairs. A BlastN search of a sequenced 1465 bp region of 16S rRNA in NCBI GenBank revealed approximately 99% genome similarity with Staphylococcus aureus. The sequence was deposited in GenBank (Accession No. MH603394). In the antibiotic sensitivity test, Kanamycin showed the highest 31.0±0.5 mm diameter zone of inhibition (DZI) against the isolated bacteria. Moreover, as a plant-derived compound, the Methanol extract of Allium sativum revealed the highest, 15.0±0.5 mm DZI. The present study would give a promising direction of identification and control of this pathogen biologically

Biodegradation of Crystal Violet dye by bacteria isolated from textile industry effluents

Industrial effluent containing textile dyes is regarded as a major environmental concern in the present world. Crystal Violet is one of the vital textile dyes of the triphenylmethane group; it is widely used in textile industry and known for its mutagenic and mitotic poisoning nature. Bioremediation, especially through bacteria, is becoming an emerging and important sector in effluent treatment. This study aimed to isolate and identify Crystal Violet degrading bacteria from industrial effluents with potential use in bioremediation. The decolorizing activity of the bacteria was measured using a photo electric colorimeter after aerobic incubation in different time intervals of the isolates. Environmental parameters such as pH, temperature, initial dye concentration and inoculum size were optimized using mineral salt medium containing different concentration of Crystal Violet dye. Complete decolorizing efficiency was observed in a mineral salt medium containing up to 150 mg/l of Crystal Violet dye by 10% (v/v) inoculums of Enterobacter sp. CV-S1 tested under 72 h of shaking incubation at temperature 35 °C and pH 6.5. Newly identified bacteria Enterobacter sp. CV-S1, confirmed by 16S ribosomal RNA sequencing, was found as a potential bioremediation biocatalyst in the aerobic degradation/de-colorization of Crystal Violet dye. The efficiency of degrading triphenylmethane dye by this isolate, minus the supply of extra carbon or nitrogen sources in the media, highlights the significance of larger- scale treatment of textile effluent