scholarly journals Bioprospecting of an Indigeneous Bacillus thuringiensis Strain G5-8-3T02 for Shrimp Culture System

Author(s):  
Caroline Nchedo Ariole ◽  
Euphemia Uchechi Agulanna

Aim: An indigenous Bacillus thuringiensis strain G5-8-3T02 earlier isolated from healthy shrimp intestine and established to safeguard Penaeus monodon from Vibrio mimicus infection was assessed as a potential candidate bacterium for drug enhancement for shrimp culture systems. Methodology: Optimal temperature, pH and salinity for growth and antibacterial activity of Bacillus thuringiensis against Vibrio mimicus were determined. The effects of enzymes (pepsin, catalase, lipase and α- amylase), pH (2-9), heat (37°C – 121°C) and surfactants (Sodium dodecyl sulphate and Tween 80) on antibacterial activity were also evaluated. Cell growth and antibacterial activity were monitored daily for 5 days via spectrophotometric method at 600 nm and agar well diffusion assay respectively. The metabolite extracted with methanol was analyzed for bioactive compounds using Gas Chromatography-Mass Spectrometry (GC-MS). Results: The optimum temperature, pH and salinity for growth and metabolite production were 35°C, pH 6-7 and 10-15 ppt. respectively. The crude extract did not totally lose its activity when treated with enzymes, various pH values, heat and surfactants. The quantitative composition of the metabolite revealed 15 bioactive compounds. The main compound produced was 2, 6, 10-Trimethyltridecane with peak area of 14.58%. Conclusion: The non-pathogenic, antagonistic, indigenous Bacillus thuringiensis strain G5-8-3T02 could be engaged in the management of vibriosis in shrimp culture since the use of antibiotics in aquaculture for disease control yields objectionable effects. The identified bioactive compounds might be valuable for drug development for shrimp culture system.

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 624
Author(s):  
Laima Česonienė ◽  
Juozas Labokas ◽  
Ina Jasutienė ◽  
Antanas Šarkinas ◽  
Vilma Kaškonienė ◽  
...  

The aim of the study was to evaluate 11 cultivars of blue honeysuckle (Lonicera caerulea L.) for bioactive compounds, antioxidant capacity, and the antibacterial activity of berries. Total phenolic contents (TPCs) and total anthocyanin contents (TACs) were established by using ethanolic extracts. For contents of organic acids and saccharides, aqueous extracts were used, and vitamin C was determined by using oxalic acid solution. DPPH• radical scavenging capacity was evaluated by using ethanolic extracts; antibacterial activity was assessed by using both ethanolic and aqueous extracts. The TPC varied from 364.02 ± 0.41 mg/100 g in ‘Vostorg’ to 784.5 ± 0.3 mg/100 g in ‘Obilnaja’, and TAC ranged from 277.8 ± 1.1 mg/100 g in ‘Čelnočnaja’ to 394.1 ± 8.4 mg/100 g in ‘Nimfa’. Anthocyanins comprised 53.8% of total phenolic contents on average. Among organic acids, citric acid was predominant, averaging 769.41 ± 5.34 mg/100 g, with malic and quinic acids amounting to 289.90 ± 2.64 and 45.00 ± 0.37 mg/100 g on average, respectively. Contents of vitamin C were 34.26 ± 0.25 mg/100 g on average. Organic acids were most effective in the inhibition of both Gram-positive and Gram-negative bacteria tested. In conclusion, berries of L. caerulea are beneficial not only for fresh consumption, but also as a raw material or ingredients of foods with high health-promoting value.


2021 ◽  
Vol 12 (1) ◽  
pp. 19
Author(s):  
Bartosz Nowak ◽  
Mateusz Kawka ◽  
Kamil Wierzchowski ◽  
Katarzyna Sykłowska-Baranek ◽  
Maciej Pilarek

Unique biosynthetic abilities revealed by plants determine in vitro cultures of hairy roots as a suitable source of pharmaceutically relevant bioactive compounds. The basic aim of the study was to examine the applicability of aerogel composed of methyltrimethoxysilane (MTMS) for immobilization of Rindera graeca hairy roots by identifying quantitative effects of biomass proliferation and naphthoquinones extracellular secretion in the aerogel-supported culture system. R. graeca hairy roots were simultaneously cultured for 28-days, as (i) nonimmobilized biomass (reference system), (ii) biomass immobilized on macroporous polyurethane foam (PUF), (iii) biomass with disintegrated MTMS aerogel, (iv) biomass immobilized on polypropylene (PP) fibers (as control), and (v) biomass immobilized on monolithic PP-reinforced MTMS aerogel. MTMS aerogel exhibited high level of biocompatibility toward R. graeca hairy roots which grew into the structure of monolithic aerogel-based constructs. Monolithic MTMS-based constructs significantly promoted the proliferation of hairy roots, resulting in 55% higher fresh mass than the reference system. The highest level of naphthoquinones productivity, i.e., 653 µg gDW−1, was noted for PUF-supported culture system.


2006 ◽  
Vol 52 (7) ◽  
pp. 651-657 ◽  
Author(s):  
Luis Morales de la Vega ◽  
J Eleazar Barboza-Corona ◽  
Maria G Aguilar-Uscanga ◽  
Mario Ramírez-Lepe

A chitinolytic enzyme from Bacillus thuringiensis subsp. aizawai has been purified and its molecular mass was estimated ca. 66 kDa by sodium dodecyl sulfate – polyacryamide gel electrophoresis (SDS–PAGE). The enzyme was able to hydrolyze chitin to chitobiosides but not carboxymethylcellulose, cellulose, pullulan, and laminarin. Optimal pH and temperature were detected at 6 and 50 °C, respectively. Stability, in the absence of substrate, was observed at temperatures less than 60 °C and pH between 5 and 8. Enzyme activity was significantly inhibited by K+ and EDTA and completely inhibited by Hg2+. Purified chitinase showed lytic activity against cell walls from six phytopathogenic fungi and inhibited the mycelial growth of both Fusarium sp. and Sclerotium rolfsii. The biocontrol efficacy of the enzyme was tested in the protection of bean seeds infested with six phytopathogenic fungi.Key words: chitinase, Bacillus thuringiensis, purification, phytopathogenic fungi.


2007 ◽  
Vol 10 (2) ◽  
pp. 137-143
Author(s):  
Joong Nam Kang ◽  
Jong Yul Roh ◽  
Sang Chul Shin ◽  
Sang-Hyun Koh ◽  
Yeong Jin Chung ◽  
...  

2009 ◽  
Vol 75 (14) ◽  
pp. 4661-4667 ◽  
Author(s):  
Alejandro Hernández-Soto ◽  
M. Cristina Del Rincón-Castro ◽  
Ana M. Espinoza ◽  
Jorge E. Ibarra

ABSTRACT Bacillus thuringiensis subsp. israelensis is the most widely used microbial control agent against mosquitoes and blackflies. Its insecticidal success is based on an arsenal of toxins, such as Cry4A, Cry4B, Cry11A, and Cyt1A, harbored in the parasporal crystal of the bacterium. A fifth toxin, Cry10Aa, is synthesized at very low levels; previous attempts to clone and express Cry10Aa were limited, and no parasporal body was formed. By using a new strategy, the whole Cry10A operon was cloned in the pSTAB vector, where both open reading frames ORF1 and ORF2 (and the gap between the two) were located, under the control of the cyt1A operon and the STAB-SD stabilizer sequence characteristic of this vector. Once the acrystalliferous mutant 4Q7 of B. thuringiensis subsp. israelensis was transformed with this construct, parasporal bodies were observed by phase-contrast microscopy and transmission electron microscopy. Discrete, ca. 0.9-μm amorphous parasporal bodies were observed in the mature sporangia, which were readily purified by gradient centrifugation once autolysis had occurred. Pure parasporal bodies showed two major bands of ca. 68 and 56 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. These bands were further characterized by N-terminal sequencing of tryptic fragments using matrix-assisted laser desorption ionization-time of flight mass spectrometry analysis, which identified both bands as the products of ORF1 and ORF2, respectively. Bioassays against fourth-instar larvae of Aedes aegypti of spore-crystal complex and pure crystals of Cry10Aa gave estimated 50% lethal concentrations of 2,061 ng/ml and 239 ng/ml, respectively. Additionally, synergism was clearly detected between Cry10A and Cyt1A, as the synergistic levels (potentiation rates) were estimated at 13.3 for the mixture of Cyt1A crystals and Cry10Aa spore-crystal complex and 12.6 for the combination of Cyt1A and Cry10Aa pure crystals.


2019 ◽  
Vol 9 (5) ◽  
pp. 204 ◽  
Author(s):  
Natthida Weerapreeyakul ◽  
Ratree Tavichakorntrakool ◽  
Aroonlug Lulitanond ◽  
Arunnee Sangka ◽  
Seksit Sungkeeree

2020 ◽  
Vol 11 (4) ◽  
pp. 5382-5387
Author(s):  
Irshad Ul Haq Bhat ◽  
Maisarah Binti Alias

The approach towards green synthetic methods has been enormously encouraged to synthesise nanoparticles for various uses. In this study, the one-pot synthetic method was adapted to synthesise silver nanoparticles (AgNPs) using Melastoma malabathricum (M. malabathricum) aqueous extract. The formation of AgNPs was confirmed by observing the results obtained by optical characterisation methods. The plasma resonance band along with shoulder at 375 nm and 595 nm, respectively, in Uv-Visible spectra supported the conversion of silver (Ag) to AgNPs reduced by functional groups present in the plant extract. The size of AgNPs was 31 nm and cubic in shape as confirmed by X-ray diffractometry (XRD) using Scherer equation. X-Ray Fluorescence (XRF) results also confirmed the presence of silver. The FTIR characterisation confirmed the presence of reducing functional groups. The antibacterial activity of AgNPs against Staphylococcus aureus (S. aureus) was carried out by disc diffusion method with increasing concentration of AgNPs, and enhanced inhibition zone was observed. The AgNPs obtained can be further explored against different bacterial strains and can a potential candidate as an antibacterial agent using the green synthetic approach.


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