Role Of Medium Composition Research Articles

PENGARUH PUPUK DAUN GROWMORE DAN HYPONEX TERHADAP PERTUMBUHAN PLANLET DENDROBIUM DIAN AGRIHORTI SECARA IN VITRO

ABSTRACT Orchid plants are one of the ornamental plant commodities that have no food reserves in their seeds and have very fine and small seed sizes making it difficult to propagate naturally. One alternative for the propagation of this plant is to carry out vegetative propagation in vitro or tissue culture. The success of plant tissue culture can not be separated from the role of media composition used. Leaf fertilizer is one of the alternative media that can be used as media material in orchid plant tissue culture because leaf fertilizers contain macro and micro nutrients that can provide nutrient intake to explants to support the growth and development of these explants. Propagation of Dian Agrihorti Dendrobium orchid plant in vitro through callus proliferation using different brands of leaf fertilizer media namely leaf fertilizer hyponex brand and growmore brand. The results of the observation showed that the most proliferative Embryogenic Callus and Proliferation Rate were produced from the treatment of adding 4 ppm growmore, namely 88.42% and 322.41%. For the best color callus parameters generated from the control treatment.

Role of media composition in biomass and astaxanthin production of Haematococcus pluvialis under two-stage cultivation.

In the present study, the effects of four different culture media on the growth, astaxanthin production and morphology of Haematococcus pluvialis LUGU were studied under two-step cultivation. The interactions between astaxanthin synthesis and secondary messengers, reactive oxygen species (ROS) and mitogen-activated protein kinases (MAPK) were also investigated. In the first green vegetative cell stage, maximal biomass productivity (86.54mgL-1day-1) was obtained in BBM medium. In the induction stage, the highest astaxanthin content (21.5mgg-1) occurred in BG-11 medium, which was higher than in any other media. The expressions of MAPK and astaxanthin biosynthetic genes in BG-11 were higher than in any other media, whereas the ROS content was lower. Biochemical and physiological analyses suggested that the ROS, MAPK and astaxanthin biosynthetic gene expression was involved in astaxanthin biosynthesis in H. pluvialis under different culture media conditions. This study proposes a two-step cultivation strategy to efficiently produce astaxanthin using microalgae.

Toxicity of silver nanoparticles to a fish gill cell line: Role of medium composition

In aqueous solutions, silver nanoparticle (AgNP) behavior is affected by a variety of factors which lead to altered AgNP size and toxicity. Our research aims to explore the effect of media composition on citrate-coated AgNP (cit-AgNP) behavior and toxicity to the cell line from rainbow trout (Oncorhynchus mykiss) gill, RTgill-W1. Three different exposure media (L15/ex, L15/ex w/o Cl and d-L15/ex) were used. These were characterized by varying ionic strength and chloride content, both of which had a dominant effect on the behaviour of cit-AgNP. Comparing the behaviour and toxicity of cit-AgNP in the different media, stronger agglomeration of cit-AgNP correlated with higher toxicity. Deposition of cit-AgNP on cells might explain the higher toxicity of agglomerated cit-AgNP compared to that of suspended cit-AgNP. The cit-AgNP concentration-response curves as a function of dissolved silver ions, and the limited prevention of toxicity by silver ligands, indicated that cit-AgNP elicited a particle-specific effect on the cells. Furthermore, the lysosomal membrane integrity was significantly more sensitive to cit-AgNP exposure than cellular metabolic activity or cell membrane integrity and showed the weakest protection by silver ligands. This revealed that cit-AgNP toxicity seems to particularly act on RTgill-W1 cell lysosomes. The newly developed low ionic strength medium, d-L15/ex, which can stabilize cit-AgNP and better mimic the freshwater environment, offers an excellent exposure solution to study cellular and molecular effects of NP to gill cells.

Xylanase production by a thermo-tolerant Bacillus species under solid-state and submerged fermentation

Effects of xylose on xylanase production by a thermophilic Bacillus sp showed diverse patterns on corn cob (CC) and wheat bran (WB) as sole carbon sources in solid- state fermentation (SSF) and submerged fermentation (SmF). Supplementation of these media with either mineral salt solution (MSS) or yeast extract peptone (YEP) also exerted variable effects. While under SSF, xylose stimulated xylanase synthesis by 44.01%, on wheat bran supplemented with MSS, it decreased the enzyme activity by 12.89% with YEP supplementation. In SmF, however the enzyme synthesis was stimulated by xylose on supplementation with both MSS and YEP by 41.38% and 27.47%, respectively. On corn cob under SSF, xylose repression was significant both with MSS (26.92%) and YEP (23.90%) supplementation. Repression by xylose also took place on corn cob and YEP (19.69%) under SmF, while significant stimulation (28.55%) was observed by MSS supplementation. The possible role of media composition and fermentation conditions in the regulation of xylanase synthesis by xylose is discussed.

What is the relationship between the metabolism of preimplantation embryos and their developmental competence?

What is the relationship between the metabolism of preimplantation embryos and their developmental competence?

Mouse embryo cleavage, metabolism and viability: role of medium composition.

The cleavage, metabolism and viability of mouse zygotes were assessed after culture in media of different ionic and metabolite composition. Medium with a high potassium concentration, characteristic of mammalian oviduct fluid, inhibited cleavage and blastocyst formation (P < 0.01). This inhibition was partially alleviated by the removal of phosphate, and subsequently abolished by supplementation with amino acids, vitamins, insulin, epidermal growth factor and transferrin (AVIET). Glucose uptake by cultured blastocysts, measured fluorimetrically, was not affected by the ionic or metabolite composition of the medium, but was significantly reduced by the inclusion of AVIET (P < 0.01). Lactate production was also significantly reduced in the presence of AVIET (P < 0.01). Calculations of metabolic activity revealed that embryos cultured in the presence of AVIET had a glycolytic activity similar to embryos developed in vivo. In contrast, embryos cultured in conventional embryo culture media exhibited an elevated glycolytic activity. Culturing embryos for 4 days in a reduced lactate concentration (4.79 mM), significantly increased fetal development after transfer, compared with embryos cultured in the concentration of lactate present in conventional embryo culture media (23.3 mM; P < 0.01). In contrast, when embryos were transferred on day 3 of culture, significantly more fetuses were obtained from embryos cultured in high levels of lactate (P < 0.01). Supplementation of medium with AVIET significantly increased resultant fetal weights after transfer (P < 0.05). This study demonstrates that different media are required to maintain embryo viability on successive days of culture, and highlights the potential limitations of employing simple salt solutions for the culture of preimplantation mammalian embryos.