Preparation of Poly(L-lactide)-b-poly(ethylene glycol)-b-poly(L-lactide)/Zinc Oxide Nanocomposite Bioplastics for Potential Use as Flexible and Antibacterial Food Packaging.

High-molecular-weight poly(L-lactide)-b-poly(ethylene glycol)-b-poly(L-lactide) (PLLA-PEG-PLLA) is a flexible and biodegradable bioplastic that has promising potential in flexible food packaging but it has no antibacterial ability. Thus, in this work, the effect of zinc oxide nanoparticles (nano-ZnOs) which have antimicrobial activity on various properties of PLLA-PEG-PLLA was determined. The addition of nano-ZnOs enhanced the crystallization, tensile, UV-barrier, and antibacterial properties of PLLA-PEG-PLLA. However, the crystallization and tensile properties of nanocomposite films decreased again as the nano-ZnO increased beyond 2 wt%. The nano-ZnO was well distributed in the PLLA-PEG-PLLA matrix when the nano-ZnO content did not exceed 2 wt% and exhibited some nano-ZnO agglomerates when the nano-ZnO content was higher than 2 wt%. The thermal stability and moisture uptake of the PLLA-PEG-PLLA matrix decreased and the film's opacity increased as the nano-ZnO content increased. The PLLA-PEG-PLLA/ZnO nanocomposite films showed good antibacterial activity against bacteria such as Escherichia coli and Staphylococcus aureus. It can be concluded that nano-ZnOs can be used as a multi-functional filler of the flexible PLLA-PEG-PLLA. As a result, the addition of nano-ZnOs as a nucleating, reinforcing, UV-screening, and antibacterial agent in the flexible PLLA-PEG-PLLA matrix may provide protection for both the food and the packaging during transportation and storage.

In vitro Antibacterial Activity of Ethanolic Tanao Si Kan Dang RD1 (Cannabis sativa L.) Extracts Against Human Antibiotic-Resistant Bacteria.

<b>Background and Objective:</b> A new strain of cannabis, <i>Cannabis sativa</i> L. Tanao Si Kan Dang RD1, has been approved and registered by the Rajamangala University of Technology Isan, Thailand. The <i>C. sativa</i> is acknowledged for its medicinal properties which demonstrated various therapeutic properties, such as anti-cancer and antibacterial activities. This study aimed to investigate the antibacterial activity of ethanolic extracts from the stems and leaves of the Tanao Si Kan Dang RD1 strain against seven antibiotic-resistant bacteria. <b>Materials and Methods:</b> The primary antibacterial activity of ethanolic Tanao Si Kan Dang RD1 extracts were determined using the disc diffusion method, while the minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) were determined using the broth microdilution method. <b>Results:</b> The largest inhibition zone, measuring 12 mm, was observed in leaf extracts against <i>Pseudomonas aeruginosa</i> 101. The lowest MIC, at 0.78 mg/mL, was obtained from stem extracts against <i>Stenotrophomonas maltophilia</i>. The lowest MBCs, at 12.5 mg/mL, were observed in leaf extracts against <i>Enterococcus faecalis</i>, <i>Acinetobacter baumannii</i>, multidrug-resistant <i>Klebsiella</i> <i>pneumoniae</i>, <i>Stenotrophomonas maltophilia</i> and <i>Pseudomonas aeruginosa</i> 101 and stem extracts against <i>Acinetobacter baumannii</i>, multidrug-resistant <i>Klebsiella pneumoniae</i>, <i>Stenotrophomonas maltophilia</i> and <i>Pseudomonas aeruginosa</i> 101. <b>Conclusion:</b> This study presents a novel finding regarding the antibacterial activity of ethanolic extracts from the leaves and stems of Tanao Si Kan Dang RD1 against antibiotic-resistant bacteria. The potential application of these cannabis plant extracts in the development of antibiotics capable of combating antibiotic-resistant pathogenic bacteria represents a promising strategy to address a significant global health concern.

Potential Antibacterial Activity of Ethanolic Curcuma longa L. Rhizome Extract Against Antibiotic-Resistant Bacteria.

<b>Background and Objective:</b> <i> Curcuma longa</i> L. rhizomes are the source of many bioactive compounds such as antitumor, antidepressant, antibacterial, anti-aging and antidiabetic. Due to the growing problem of antibiotic-resistant bacteria, it is necessary to find new sources of antibiotics. This research aimed to investigate the antibacterial activity of ethanolic <i>Curcuma longa</i> L. rhizomes extract against <i>Proteus mirabilis, Acinetobacter baumannii</i> and Multidrug-Resistant <i>Klebsiella pneumoniae</i> (MDR-K). <b>Materials and Methods:</b> Dry <i>Curcuma longa</i> L. rhizomes were extracted with ethanol. The agar diffusion method was used as the primary screening of antibacterial activity determination. The broth dilution method was used to measure the MIC and MIC of the extract. <b>Results:</b> It presented the largest diameter of the inhibition zone at 0.9 mm against <i>Proteus mirabilis</i>, followed by 0.8 mm against MDR-K. The lowest MIC and MBC values were at 0.048 and 0.39 mg mL¹ against <i>Proteus mirabilis</i>, followed by 0.195 and 6.25 mg mL¹ against MDR-K. The ethanolic <i>Curcuma longa</i> L. rhizomes extract did not affect <i>Acinetobacter baumannii</i>. <b>Conclusion:</b> The new finding of this research was that the ethanolic extract from <i>Curcuma longa</i> L. rhizomes can eliminate <i>Proteus mirabilis</i> and MDR-K that can be applied to treating antibiotic-resistant bacterial infectious diseases in the hospital.

Effects of Edible Insects on the Mycelium Formation of Cordyceps militaris.

<b>Background and Objective:</b> <i>Cordyceps militaris </i>is a potential edible medicinal mushroom which containing various biological activity such as anti-inflammatory, anti-ageing, anti-protozoal and anti-microbial. The compositions of <i>C. militaris</i> media were composed of carbon source, nitrogen source and other additives. This research aimed to evaluate the effect of edible insects on the <i>C. militaris </i>mycelium formation. <b>Materials and Methods:</b> Seven edible insects including <i>Bombyx mori </i>L., <i>Samia ricini</i> D., <i>Acheta domesticus</i> L., <i>Gryllus bimaculatus</i> De Geer, <i>Tenebrio molitor</i> L., <i>Rhynchophorus ferrugineus</i> and <i>Lethocerus indicus</i> were used as nitrogen source supplemented in Potato Dextrose Agar (PDA) and the mycelium formation of each edible insects at day 7, 14 and 21 were recorded. <b>Results:</b> The results of nitrogen source from a boiled edible insect at day 21 indicated that the highest colony diameter at 88.00 mm was obtained when cultured with PDA+<i>B. mori</i> L. The results of nitrogen source from a dried edible insect at day 21 presented that the highest diameter at 84.33 mm was obtained from cultured using PDA+<i>A. domesticus</i> L. <b>Conclusion:</b> The suitable boiled and dried edible insects for the supplement in PDA were boiled <i>B. mori</i> L. and dried <i>A. domesticus </i>L. This is the first report about PDA supplemented with edible insects that can be increased the <i>C. militaris</i> mycelium formation which the initial stage that important for <i>C. militaris </i>cultivation.

A New Potential Source of Anti-pathogenic Bacterial Substances from Zamioculcas zamiifolia (Lodd.) Engl. Extracts.

BACKGROUND AND OBJECTIVE: The increase of antibiotic-resistant bacteria is a problem for global health that needs to find new antibiotic drugs. The plant is the potential source of antibiotic substances that important to solve the antibiotic-resistant bacteria. This study was aimed to evaluate the antibacterial activity of Zamioculcas zamiifolia stem extracts against nine human pathogenic bacteria. MATERIALS AND METHODS: Z. zamiifolia stems were extracted with five extraction solvents. The screening of antibacterial activity of stem extract was measured using agar disc diffusion assay. The Minimal Inhibition Concentration (MIC) and Minimal Bactericidal Concentration (MBC) values of extracts were determined using the broth microdilution assay and colorimetric assay. RESULTS: The results indicated that the lowest MIC value of 0.09 mg mL-1 against Staphylococcus aureus TISTR 1466 was obtained from hexane extraction. The lowest MBCs value of 1.56 mg mL-1 against Bacillus cereus TISTR 2373, Listeria spp. and Escherichia coli TISTR 527 were obtained from ethanol and methanol extractions. CONCLUSION: The ethanolic and methanolic stem extracts of Z. zamiifolia demonstrated the highest anti-human pathogenic bacterial activity. This is the first report to demonstrate the high potential of antibacterial substance from Z. zamiifolia stem extracts, which can be developed further as a natural drug for treating bacterial infectious diseases.

Evaluation of the Antibacterial Activity of Spathiphyllum wallisii Extracts Against Human Pathogenic Bacteria.

BACKGROUND AND OBJECTIVE: The urgent of finding new antibiotics due to the rising of antibiotic-resistant bacteria. The plant is the main source of new antibiotic substances. The purpose of this research was to evaluate the antibacterial activity of Spathiphyllum wallisii extracts against nine human pathogenic bacteria. MATERIALS AND METHODS: The stalks, leaf, rhizome and root of S. wallisii were extracted by using hexane, dichloromethane, ethyl acetate, ethanol and methanol. The disc diffusion assay was used to screen the antibacterial activity of S. wallisii extracts. Broth dilution and colorimetric assay were used to determine the Minimal inhibitory Concentration (MIC) and Minimal Bactericidal Concentration (MBC) values of extracts. RESULTS: The lowest MIC values at 0.048 mg mL-1 were presented in the stalks extract with dichloromethane, ethyl acetate, methanol and ethanol against B. subtilis TISTR 008, the leaf extracted with hexane, dichloromethane, ethyl acetate, methanol and ethanol against B. subtilis TISTR 008; the leaf extracted with ethyl acetate, methanol and ethanol against S. aureus TISTR 1466, the leaf extracted with dichloromethane, ethyl acetate, methanol and ethanol against S. aureus PK; the rhizome extracted with methanol against S. aureus PK. The lowest of MBC value of 0.048 mg mL-1 was obtained from methanolic rhizome extract against B. subtilis TISTR 008. CONCLUSION: The methanolic rhizome extract of S. wallisii demonstrated the highest of pathogenic bacterial growth inhibition. This is the first report about the antibacterial activity of S. wallisii extracts that will add new information in natural drug discovery and development in industrial pharmacology.

Pseudomonas stutzeri CM1, Novel Thermotolerant Cellulase- Producing Bacteria Isolated from Forest Soil.

BACKGROUND AND OBJECTIVE: Cellulase is an important enzyme that useful for agricultural residue hydrolysis such as plant stover, molasse, rice straw. Thermotolerant cellulases are required to apply in textile, food, detergent, biofuels and pharmaceutical applications. This research aimed to isolate the thermotolerant cellulase-producing bacteria from forest soil and to determine cellulase activity from isolated bacteria. MATERIALS AND METHODS: Soil samples were collected from the Roi Et Rajabhat University forest. One gram of soil sample was mixed with Luria-Bertani (LB) broth medium and incubated at 37°C with shaking at 150 rpm for 24 h. The cultured broth was streaked on LB agar plate and incubated at 37°C for 24 h. Cellulase-producing bacteria were isolated using Carboxymethylcellulose (CMC) agar plate. Four bacterial isolates which presented a clear zone on CMC agar plate after flooded with iodine solution, named CM1, CM2, CM3 and CM4. Cellulase activity of 4 isolated bacteria was determined against various pH (pH 4-8) and temperature (50-100°C). RESULTS: The results indicated that CM1 isolate showed the highest cellulase activity at 0.074 unit mL-1 at 80°C and pH5. All isolates were identified using 16S rRNA gene sequencing. The results indicated that CM1, CM3 and CM4 were identified as Pseudomonas stutzeri. while isolate CM2 was Bacillus subtilis. CONCLUSION: This is the first report presenting the thermotolerant cellulase produced by Pseudomonas stutzeri. The thermotolerant cellulase produced from Pseudomonas stutzeri in this study will be useful in many industrial processes using cellulase at high temperatures.

Multiplex polymerase chain reaction used for bovine embryo sex determination.

Widely used bovine sexing primers were compared in terms of suitability in determining the sex of bovine embryos. Under optimized multiplex PCR conditions, the ConBV/ConEY couple primers did not show accurate results when combined together in multiplex PCR, but worked well when the couple primers were used separately. The S4BF/S4BR primers showed accurate results; however, some unexpected bands were detected. When the BY/BSP couple primers were used to determine one-cell, two-cell, four-cell and eight-cell stage embryos of known sexed SCNT-derived embryos, the results showed 100% accuracy. The BY/BSP couple primers were also able to identify the sex of one-cell and two-cell IVF-derived embryos.