Strain distribution and in planta production of an extracellular polysaccharide depolymerase from Bradyrhizobium japonicum

1992 ◽  
Vol 38 (8) ◽  
pp. 857-861 ◽  
Author(s):  
Michael F. Dunn ◽  
Arthur L. Karr
Keyword(s):  
Bradyrhizobium Japonicum ◽  
Root Nodules ◽  
Extracellular Polysaccharide ◽  
Extracellular Polysaccharides ◽  
Neutral Sugar ◽  
In Planta ◽  
In Vitro Production ◽  
Polysaccharide Composition ◽  
Vitro Production

Thirty-four strains of Bradyrhizobium japonicum were screened for the in vitro production of an extracellular polysaccharide depolymerase active against the B. japonicum acidic extracellular polysaccharide that contains mannose, glucose, galactose, and 4-O-methylgalactose as neutral sugar components. Over 90% of tested strains producing this type of extracellular polysaccharide also produced the extracellular polysaccharide depolymerase, whereas strains producing a compositionally different extracellular polysaccharide did not. In addition, representatives of species related to B. japonicum by extracellular polysaccharide composition or host range were also phenotypically depolymerase negative. Depolymerase was also present in soybean root nodules formed by B. japonicum strain 2143. In contrast to the cell-associated depolymerase activity found in free-living cells of this strain, most of the depolymerase activity present in nodules is free of the bacteroids. The widespread occurrence of the depolymerase among B. japonicum strains and the spatiotemporal distribution of its activity in planta are consistent with the enzyme playing a role in the removal of surface extracellular polysaccharide from the microorganism during the infection of nodulation process. Key words: Bradyrhizobium japonicum, soybean, extracellular polysaccharides, extracellular polysaccharide depolymerase, bacteroids.

THE IN VITRO PRODUCTION OF ANDROGENS BY FOLLICULAR TISSUE OF RABBITS

1964 ◽  
Vol 47 (2) ◽  
pp. 306-313 ◽  
Author(s):  
Denis Gospodarowicz
Keyword(s):  
In Vitro Production ◽  
Vitro Production

ABSTRACT Incubation in vitro of rabbit follicles in separate experiments with dehydroepiandrosterone-14C (DHEA-14C), progesterone-14C and pregnenolone-3H in the presence of FSH gave the following results: 39 % of the radioactivity of DHEA-14C is converted to androstenedione and testosterone, while only 3 % of the radioactivity of either progesterone-14C or pregnenolone-3H is found in the androgen fraction. From the ratio of testosterone to androstenedione formed from the three precursors, the results are interpreted to mean that DHEA and pregnenolone, and not progesterone, are precursors of androgens in the follicle.

Oxygenation of 18-hydroxycorticosterone as the final reaction for aldosterone biosynthesis

1984 ◽  
Vol 107 (3) ◽  
pp. 395-400 ◽  
Author(s):  
Itaru Kojima ◽  
Etsuro Ogata ◽  
Hiroshi Inano ◽  
Bun-ichi Tamaoki
Keyword(s):  
Carbon Monoxide ◽  
Hydroxysteroid Dehydrogenase ◽  
Dependent Manner ◽  
In Vitro Production ◽  
Mitochondrial Preparation ◽  
Final Reaction ◽  
Vitro Production ◽  
Dose Dependent ◽  
Cytochrome P 450

Abstract. Incubation of 18-hydroxycorticosterone with the sonicated mitochondrial preparation of bovine adrenal glomerulosa tissue leads to the production of aldosterone, as measured by radioimmunoassay. The in vitro production of aldosterone from 18-hydroxycorticosterone requires both molecular oxygen and NADPH, and is inhibited by carbon monoxide. Cytochrome P-450 inhibitors such as metyrapone, SU 8000. SU 10603, SKF 525A, amphenone B and spironolactone decrease the biosynthesis of aldosterone from 18-hydroxycorticosterone. These results support the conclusion that the final reaction in aldosterone synthesis from 18-hydroxycorticosterone is catalyzed by an oxygenase, but not by 18-hydroxysteroid dehydrogenase. By the same preparation, the production of [3H]aldosterone but not [3H]18-hydroxycorticosterone from [1,2-3H ]corticosterone is decreased in a dose-dependent manner by addition of non-radioactive 18-hydroxycorticosterone.

scholarly journals Nano-Elicitation as an Effective and Emerging Strategy for In Vitro Production of Industrially Important Flavonoids

2021 ◽  
Vol 11 (4) ◽  
pp. 1694
Author(s):  
Amna Komal Khan ◽  
Sidra Kousar ◽  
Duangjai Tungmunnithum ◽  
Christophe Hano ◽  
Bilal Haider Abbasi ◽  
...  
Keyword(s):  
World Market ◽  
Culture Technique ◽  
In Vitro Cultures ◽  
Defense System ◽  
In Vitro Production ◽  
Metallic Oxide ◽  
Global Demand ◽  
Over Exploitation ◽  
Vitro Production

Flavonoids represent a popular class of industrially important bioactive compounds. They possess valuable health-benefiting and disease preventing properties, and therefore they are an important component of the pharmaceutical, nutraceutical, cosmetical and medicinal industries. Moreover, flavonoids possess significant antiallergic, antihepatotoxic, anti-inflammatory, antioxidant, antitumor, antiviral, and antibacterial as well as cardio-protective activities. Due to these properties, there is a rise in global demand for flavonoids, forming a significant part of the world market. However, obtaining flavonoids directly from plants has some limitations, such as low quantity, poor extraction, over-exploitation, time consuming process and loss of flora. Henceforth, there is a shift towards the in vitro production of flavonoids using the plant tissue culture technique to achieve better yields in less time. In order to achieve the productivity of flavonoids at an industrially competitive level, elicitation is a useful tool. The elicitation of in vitro cultures induces stressful conditions to plants, activates the plant defense system and enhances the accumulation of secondary metabolites in higher quantities. In this regard, nanoparticles (NPs) have emerged as novel and effective elicitors for enhancing the in vitro production of industrially important flavonoids. Different classes of NPs, including metallic NPs (silver and copper), metallic oxide NPs (copper oxide, iron oxide, zinc oxide, silicon dioxide) and carbon nanotubes, are widely reported as nano-elicitors of flavonoids discussed herein. Lastly, the mechanisms of NPs as well as knowledge gaps in the area of the nano-elicitation of flavonoids have been highlighted in this review.

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