Screening and Characterization of Nitrite-Degrading Bacterial Isolates Using a Novel Culture Medium

In this study,a novel culture medium that simulates shrimp pond conditions was established to screen nitrite-degrading isolates.The medium was supplemented with nitrite as a nitrogen source and shrimp feed as the major carbon source,to achieve the high nitrogen and low carbon nutritional status found in shrimp farming ponds.Screening using this medium identified potent denitrifying Bacillus isolates,among which Bacillus subtilis M7-1 was considered best.M7-1 was able to completely degrade nitrite-N in 24 h without much consumption of dissolved oxygen.Efficient denitrification activity took place in liquid cultures within a set of non-stringent ranges of pH(5.0–9.0),salinity(0–30)and temperature(25–35℃).The denitrifying enzyme gene was amplified,sequenced and further identified as nirS type.In biosecurity assessments,M7-1 had no negative effects on shrimps at a dose of 106 cfu mL−1.M7-1 could therefore be used in aquaculture to reduce and control the nitrogen concentration,and to promote the development of sustainable and healthy culture systems.

Isolation and Screening of Oenococcus oeni and Its Medium Optimization

[Objectives] This study was conducted to further improve the application of Oenococcus oeni in the wine brewing industry. [Methods] O. oeni was isolated, screened, and identified, and medium optimization was performed to determine the best medium, temperature and oxygen conditions. [Results] O. oeni grew better in mFT80 medium, and the culture conditions were 25 ℃ and an anaerobic condition. [Conclusions] This study provides a reference for the development of China’s wine industry.

Screening of Optimal Differentiation Medium to Lonicera edulis

An excellent Lonicera edulis strain, L1-8 that was bred by Northeast Institute of Geography and Agro-ecology, Chinese Academy of Sciences, was used as material in this research. The axillary buds of its dormant branches were used as explants. A fourfactor and four-level orthogonal test was designed in order to choose the best differentiation medium for providing the technical support of Lonicera edulis micropropagation. The results showed that the culture medium and concentration of 6-BA were the main factors, and the best differentiation condition was MS culture medium containing 2.0 mg · L-1 6-BA, 0.3 mg · L-1 IBA and 1.5 mg · L-1 GA3.

Preliminary Study on in Vitro Germination of Yangmei Pollen

[Objectives]To explore the conditions for in vitro culture of Yangmei pollen.[Methods]Experiments were conducted on the germination characteristics of three types of Yangmei pollen using in vitro culture and germination method.[Results]The suitable medium ratio for the germination of Yangmei pollen was 10%sucrose+0.01%borax+1%agar;the cultivation temperature of 30℃was more suitable for the germination of Yangmei pollen than 25℃;through analysis of variance,among the three types of Yangmei pollen,pollen of male 1 had the strongest viability,and it was the better pollination type.[Conclusions]The research could provide certain basis for introduction and cultivation of Yangmei and improving hybrid breeding effect.

Characteristics of a kHz helium atmospheric pressure plasma jet interacting with two kinds of targets

This study investigates the influence of two types of target,skin tissue and cell culture medium,with different permittivities on a k Hz helium atmospheric pressure plasma jet(APPJ)during its application for wound healing.The basic optical-electrical characteristics,the initiation and propagation and the emission spectra of the He APPJ under different working conditions are explored.The experimental results show that,compared with a jet freely expanding in air,the diameter and intensity of the plasma plume outside the nozzle increase when it interacts with the pigskin and cell culture medium targets,and the mean velocity of the plasma bullet from the tube nozzle to a distance of 15 mm is also significantly increased.There are also multiple increases in the relative intensity of OH(A^(2)Σ→X^(2)Π)and O(3p^(5)S-3s^(5)S)at a position 15 mm away from nozzle when the He APPJ interacts with cell culture medium compared with the air and pigskin targets.Taking the surface charging of the low permittivity material capacitance and the strengthened electric field intensity into account,they make the various characteristics of He APPJ interacting with two different targets together.

Study on Tissue Culture and Adventitious Bud Induction of Eucheuma striatum

This study aimed to investigate the aseptic treatment and disinfection of E.striatum explants and the effects of three liquid culture medium(PES,PESI,f/2) and plant hormones on adventitious bud induction from explants.The results showed that the vast majority of explants disinfected by combined treatment exhibited good growth and normal color with an average mortality rate of only 9%.E.striatum explants exhibited the best growth in PES liquid medium and the survival rate reached 66.67%at 40 d after culture.Under different concentrations(0.5,2,5 mg/L) of 6-BA,the induction rate of E.striatum explants was significantly higher than that in control group,but no remarkable differences were found in the induction of adventitious buds from E.striatum explants.In PES liquid medium containing 6-BA and 2,4-D,the adventitious bud induction rate was 90%and the average number of induced adventitious buds was 6.63.

Study on Optimization of Culture Conditions for Wild Isaria cicadae Miquel Liquid Strain

[Objectives] To study the effect of different culture conditions on the growth of wild I. cicadae Miq. liquid strain. [Methods]The I. cicadae Miq. strain was inoculated into the liquid culture medium with different carbon sources,nitrogen sources,micronutrients and p H,cultured in the constant temperature shaking incubator with rotating speed of 120 r/min at 19℃,and the mycelium pellet diameter,density and weight were compared between different treatments. [Results] The results showed that the optimum components of I. cicadae Miq.strain liquid included soluble starch,milk powder and vitamin B_(12),and the optimum p H was 5. 0-6. 0. [Conclusions] Soluble starch was the most suitable carbon source for the culture medium of I. cicadae Miq. liquid strain; milk powder was the most suitable nitrogen source for the culture medium of I. cicadae Miq. liquid strain; the most suitable p H was 5. 0-9. 0 for the mycelial growth of I. cicadae Miq.; the formula and mixture ratio of the optimum culture medium for the growth of liquid strain were determined.

In Vitro Propagation of Grapevine Cultivars with Potential for South of Brazil

The micropropation is an important biotechnological tool for obtaining and maintaining mother vine plants with high quality plant health. The objective was to evaluate the establishment and multiplication in vitro and ex vitro acclimatization of grape genotypes with potential for Southern Brazil. Vine nodal segments were cultured in five culture medium formulations without adding growth regulators. It was evaluated the number of leaves and roots, length of roots and shoots, replication rate, relative chlorophyll index, percentage of regenerated and rooted plants, dry biomass of shoot, root and total plants grown in vitro and after acclimatization. In vitro propagation of IAC 571-6 rootstock and cv. Poloskei Muskotaly through nodal segments provided high rates of regeneration and rooting. High survival rates were obtained in the acclimatization of IAC 571-6 and P?l?skei Muskotaly. Considering all the variables, the culture medium Roubelakis showed the best growth rates and development for shoots and roots, and in vitro multiplication rate for IAC 571-6 and Poloskei Muskotaly grape varieties.

Character of cell-free genomic DNA in embryo culture medium and the prospect of its clinical application in preimplantation genetic testing

There is increasing evidence that cell-free DNA (cfDNA) in spent culture media (SCM) can be amplified for genetic testing. Therefore, this paper reviews the characteristics of cfDNA, including its fragment size, amount, origin, as well as some factors affecting the success rate of its amplification, together to provide researchers with a more comprehensive perspective on embryonic cfDNA. The origin of cfDNA in SCM is complicated and poses challenges to the interpretation of genetic test results. Advanced molecular techniques should distinguish between embryonic and contaminated DNA to maximize the success rate of amplification and analysis. Recent data showed that the type of culture medium, assisted hatching or not, the type of amplification kit, and fresh or thawed embryos were not related to the success rate of amplification, but the length of culture time might affect the success rate. The longer culture time, the more cfDNA is available in the SCM. Then we focused on the concordance between trophectoderm (TE), inner cell mass, whole embryo, and embryonic cfDNA. Despite successful amplification, the concordance between TE and embryonic cfDNA was low. In summary, non-invasive genetic testing using SCM could represent a major advance in future single embryo selection, however, contamination and timing for media collection are key factors affecting the results, and current non-invasive cfDNA testing should not be directly applied to clinical practice. Further research is needed to improve the methods used for testing techniques and genetic analysis to achieve greater accuracy and trace its origins before it can be used in the clinics.

From nature to nurture:Essence and methods to isolate robust methanotrophic bacteria

Methanotrophic bacteria are entities with innate biocatalytic potential to biofilter and oxidize methane into simpler compounds concomitantly conserving energy,which can contribute to copious industrial applications.The future and efficacy of such industrial applications relies upon acquiring and/or securing robust methanotrophs with taxonomic and phenotypic diversity.Despite several dramatic advances,isolation of robust methanotrophs is still a long-way challenging task with several lacunae to be filled in sequentially.Methanotrophs with high tolerance to methane can be isolated and cultivated by mimicking natural environs,and adopting strategies like adaptive metabolic evolution.This review summarizes existent and innovative methods for methanotrophic isolation and purification,and their respective applications.A comprehensive description of new insights shedding light upon how to isolate and concomitantly augment robust methanotrophic metabolism in an orchestrated fashion follows.

Methods for extracellular vesicle isolation from cancer cells

Cells are known to release different types of vesicles such as small extracellular vesicles(sEVs)and large extracellular vesicles(LEVs).sEVs and LEVs play important roles in intercellular communication,pre-metastatic niche formation,and disease progression;both can be detected cell culture media and biological fluids.sEVs and LEVs contain a variety of protein and RNA cargo,and they are believed to impact many biological functions of the recipient cells upon their internalization or binding to cell surface proteins.It has recently been established that standard isolation techniques,such as differential ultracentrifugation,yield a mixed population of EVs.However,density gradient ultracentrifugation has been reported to allow the isolation of sEVs without cellular debris.Here,we describe the most common methods used to isolate sEVs from cell culture medium,mouse and human plasma,and a new technique for isolating sEVs from tissues as well.This article also provides detailed procedures to isolate LEVs.