Academic literature on the topic 'Sterilization of medium without autoclaving'

Micropropagation techniques changed the production of clonal plantlets in the world. However, the high costs of micropropagated plantlets continue as the main constraint for the expansion of the technique. This paper aimed to test the use of the chemical sterilization of culture medium using chlorine dioxide (ClO2) for in vitro cultivation of gerbera. There was used gerbera in vitro shoots in the stage of rooting for these experiments, using 0.0035%, 0.0070% and 0.0105% of chlorine dioxide in the culture medium. Also, peracetic acid was tested previously for sterilization, but resulted in microbial contamination. Chemical sterilization of the culture medium was successfully using ClO2 at 0.0035% to 0.0105% (100% decontamination) at rooting and elongation stage of gerbera with production of plantlets with similar (number of leaves, total and root fresh weight) or higher quality (mainly aerial part) at rooting/elongation stage, compared with autoclaved culture medium. The increase of concentration of ClO2 also resulted in increasing of height and fresh weight of aerial part of gerberas. The ClO2 could replace the autoclaving with production of sterilized culture medium without phytotoxic problems to gerbera in vitro cultivation.

Luria–Bertani broth (LB) culture medium is a commonly used bacterial culture medium in the laboratory. The nutrient composition, concentration, and culture conditions of LB medium can influence the growth of microbial strains. The purpose of this article is to demonstrate the impact of LB liquid culture medium on microbial growth under different sterilization conditions. In this study, LB medium with four different treatments was used, as follows: A, LB medium without treatments; B, LB medium with filtration; C, LB medium with autoclaving; and D, LB medium with autoclaving and cultured for 12 h. Subsequently, the protein levels and antioxidant capacity of the medium with different treatments were measured, and the effects of the different LB medium treatments on the growth of microorganisms and metabolites were determined via 16s rRNA gene sequencing and metabolomics analysis, respectively. Firmicutes and Lactobacillus were the dominant microorganisms, which were enriched in fermentation and chemoheterotrophy. The protein levels and antioxidant capacity of the LB medium with different treatments were different, and with the increasing concentration of medium, the protein levels were gradually increased, while the antioxidant capacity was decreased firstly and then increased. The growth trend of Bacillus subtilis, Bacillus paralicheniformis, Micrococcus luteus, and Alternaria alternata in the medium with different treatments was similar. Additionally, 220 and 114 differential metabolites were found between B and C medium, and between C and D medium, which were significantly enriched in the “Hedgehog signaling pathway”, “biosynthesis of plant secondary metabolites”, “ABC transporters”, “arginine and proline metabolism”, and “linoleic acid metabolism”. LB medium may be a good energy source for Lactobacillus growth with unsterilized medium, and LB medium filtered with a 0.22 μm filter membrane may be used for bacterial culture better than culture medium after high-pressure sterilization. LB medium still has the ability for antioxidation and to keep bacteria growth whether or not autoclaved, indicating that there are some substances that can resist a high temperature and pressure and still maintain their functions.

This study assessed the feasibility of using bleached cellulose pulp from Eucalyptus wood as a feedstock for the production of itaconic acid by fermentation. Additionally, different process strategies were tested with the aim of selecting suitable conditions for an efficient production of itaconic acid by the fungus Aspergillus terreus. The feasibility of using cellulose pulp was demonstrated through assays that revealed the preference of the strain in using glucose as carbon source instead of xylose, mannose, sucrose or glycerol. Additionally, the cellulose pulp was easily digested by enzymes without requiring a previous step of pretreatment, producing a glucose-rich hydrolysate with a very low level of inhibitor compounds, suitable for use as a fermentation medium. Fermentation assays revealed that the technique used for sterilization of the hydrolysate (membrane filtration or autoclaving) had an important effect in its composition, especially on the nitrogen content, consequently affecting the fermentation performance. The carbon-to-nitrogen ratio (C:N ratio), initial glucose concentration and oxygen availability, were also important variables affecting the performance of the strain to produce itaconic acid from cellulose pulp hydrolysate. By selecting appropriate process conditions (sterilization by membrane filtration, medium supplementation with 3 g/L (NH4)2SO4, 60 g/L of initial glucose concentration, and oxygen availability of 7.33 (volume of air/volume of medium)), the production of itaconic acid was maximized resulting in a yield of 0.62 g/g glucose consumed, and productivity of 0.52 g/L·h.

Kratom, Mitragyna speciosa (Korth.) Havil. is a medicinal plant native to Southeast Asia that is renowned for its therapeutic properties and potential in treating various ailments. Despite its significance, the cultivation and propagation of Kratom have been limited. The purpose of the present study was to develop a cost-effective micropropagation protocol for Kratom by investigating the disinfection efficiency and cost-effectiveness of various chemical disinfectants, optimizing plant growth regulator concentrations, and assessing cost-effective media sterilization methods. The results demonstrated that double disinfection with commercial bleach at 20% and 15% for 5 min each was the most cost-effective treatment for surface disinfection of Kratom seeds, achieving a high disinfection rate (96.67±2.89%) and survival rate (73.33±2.89%) at a relatively low cost (1.46 baht per experiment) compared to mercuric chloride (HgCl2) treatments. The evaluation of benzyladenine (BA) and naphthaleneacetic acid (NAA) effects on in vitro growth revealed that the control treatment (MS (Murashige and Skoog medium) without growth regulators) exhibited the best overall growth performance. Among the low-cost disinfectants tested for the culture medium, while autoclaving offers superior disinfection efficacy, commercial bleach at 2 ml/l emerged as the most cost-effective option, especially for resource-limited operations. The final choice, however, should align with specific operational requirements, including scale, resources, and the need for complete disinfection. The successful establishment of a cost-effective micropropagation protocol using low-cost chemical disinfectants and optimized plant growth regulator concentrations can significantly reduce the production costs associated with tissue culture techniques, making the micropropagation of Kratom more economically viable and accessible for large-scale production. The findings from this research provide insights into cost-effective micropropagation methods for Kratom, which will prove valuable for future studies and applications in the field.

The aim of this study was to check the use of the following gelling agents: the xanthan gum “Adicel®” and the stabilizer “Super Liga Neutra®” to replace agar in the in vitro rooting phase of Gerbera hybrida cv. Essandre. Additionally, the possibility of using chemical sterilization of both culture media and glassware with sodium hypochlorite to replace autoclaving was analyzed. The gelling agents, xanthan gum “Adicel®” and the stabilizer “Super Liga Neutra®” were tested at the following concentrations (g L-1): 7; 9; 11; 13; 15; 17; 19; and 21. No concentrations of Super Liga Neutra® provided effective solidification. Concentrations of 17 and 21 g of Adicel® provided a good gelling of the culture medium, which was compared to the medium containing agar (control) with two types of sterilization: autoclaving (for 20 and 40 minutes) and chemical sterilization. Autoclaving for 20 minutes did not provide effective elimination of contamination in the culture medium containing xanthan gum; this only occurred when autoclaving time increased to 40 minutes. Plant development in culture media containing 17 and 21 g of xanthan gum, either sterilized by autoclaving for 40 minutes or at a concentration of 17 g xanthan gum using sodium hypochlorite, was statistically the same as the control that contained agar. However, plant development at a concentration of 21g of xanthan gum in a sterilized medium using sodium hypochlorite was lower than that observed in media containing agar.

ABSTRACT Objective: evaluate the sterilization of human teeth irradiated by microwaves. Methods: Sixty human third molars are divided into three groups (n = 20): G1 without sterilization (negative control); G2 - autoclaving for 20 minutes 1Kgf/cm2 at 120 ° C (positive control); G3 - sterilization in a microwave vessel containing 200ml of distilled water in a microwave irradiated at 650W for 3 minutes. Results: No culture media of G2 and G3 presented contamination after autoclaving and microwave sterilization. Conclusion: Autoclave sterilization and microwave sterilization were effective decontamination methods under the experimental conditions tested.