Ethylene plays a crucial role in various biological processes and therefore its biosynthesis is strictly regulated by multiple mechanisms. Posttranslational regulation, which is pivotal in controlling ethylene biosynthesis, impacts 1-aminocyclopropane 1-carboxylate synthase (ACS) protein stability via the complex interplay of specific factors. Here, we show that the Arabidopsis thaliana protein phosphatase type 2C, ABI1, a negative regulator of abscisic acid signaling, is involved in the regulation of ethylene biosynthesis under oxidative stress conditions. We found that ABI1 interacts with ACS6 and dephosphorylates its C-terminal fragment, a target of the stress-responsive mitogen-activated protein kinase, MPK6. In addition, ABI1 controls MPK6 activity directly and by this means also affects the ACS6 phosphorylation level. Consistently with this, ozone-induced ethylene production was significantly higher in an ABI1 knockout strain (abi1td) than in wild-type plants. Importantly, an increase in stress-induced ethylene production in the abi1td mutant was compensated by a higher ascorbate redox state and elevated antioxidant activities. Overall, the results of this study provide evidence that ABI1 restricts ethylene synthesis by affecting the activity of ACS6. The ABI1 contribution to stress phenotype underpins its role in the interplay between the abscisic acid (ABA) and ethylene signaling pathways.
Potato protein is recognized as one of the most valuable nonanimal proteins due to the high content of essential amino acids. So far, it has not been used in human nutrition on a large scale due to technological limitations regarding its acquisition. In this study, the protein fraction of potato juice was concentrated with the use of membrane separation. The obtained potato juice protein concentrate (PJPC) was characterized in terms of nutritional value and biological activity, and the amino acid composition, mineral content, and antioxidant properties were determined. Moreover, in vitro cytotoxic activity against cancer cells of the gastrointestinal tract was investigated. The results of the present study indicate that PJPC is an excellent source of lysine and threonine, while leucine is its limiting amino acid, with an amino acid score (AAS) of 65%. Moreover, PJPC contains substantial amounts of Fe, Mn, K, and Cu. As demonstrated experimentally, PJPC is also characterized by higher antioxidant potential than potato itself. Biological activity, however, is not limited to antioxidant activity alone. Cytotoxicity studies using a gastric cancer cell line (Hs 746T), a colon cancer cell line (HT-29), and human colon normal cells (CCD 841 CoN) proved that PJPC is characterized by selective activity against cancer cells. It can thus be concluded that the developed method of producing protein concentrate from potato juice affords a product with moderate nutritional value and interesting biological activity.
27 February 2013 in Journal of Industrial Microbiology and Biotechnology
This is the first report on the ability of Yarrowia lipolytica strains to produce 2-phenylethanol (2-PE), which has not been identified for this species to date. 2-PE is a valuable aroma compound of rose-like odor. Its isolation from the other than microbial source—rose petals, is limited by the substrate availability. Thus, this chemical compound constitutes an attractive product for biotechnological conversions. To date, the ability to produce 2-PE has been described for such genera as Saccharomyces sp., Kluyveromyces sp., Geotrichum sp., and Pichia sp. This report provides evidence that Y. lipolytica is a novel 2-PE producer. Moreover, the titers of 2-PE obtained in Y. lipolytica NCYC3825 non-optimized cultures, nearly 2 g/l, are competitive to titers obtained by the other species.
Published data indicate that cricket powder (CP) is a good source of not only protein, fat and fiber, but also minerals. Due to the fact that this product naturally does not contain gluten, it is an interesting addition to the enrichment of gluten-free foods. This paper is a report on the results of starch substitution with CP (at 2%, 6% and 10%) on the properties of dough and bread. The rheology of dough and the texture of the final product were studied. While the changes caused in the dough by the introduction of CP were not pronounced, the bread obtained from it was characterized by significantly increased hardness and improved consistency. Analyses of water behavior at the molecular level with the use of 1H Nuclear Magnetic Resonance (NMR) indicated that CP altered both the bound and bulk water fractions. Moreover, examination of water activity revealed a decreased rate of water transport in samples of bread that contained CP. These results indicate improved availability of water to the biopolymers of bread, which likely plays a role in shaping the textural properties of the product.
2 January 2022 in Critical Reviews in Plant Sciences
Potatoes (Solanum tuberosum L.), consumed daily by millions of people around the world, are one of the most important food crops. Potato juice (PJ) is a by-product of the starch production process and contains all the constituents of potato tubers except starch and fiber. A large volume of PJ is produced annually during the starch campaign. Currently, it can, at best, serve as a source of protein for animal nutrition. The proteins are isolated using an acidification and thermal treatment, and the remaining liquid fraction is generally considered a problematic waste. Literature reports indicate that PJ is a valuable raw material not only because of its high nutritional value but, above all, due to the biological activity that can facilitate the treatment of certain gastrointestinal tract diseases. Medicinal use of PJ in folk medicine dates back to the beginning of the 19th century when it was used to alleviate the symptoms of gastrointestinal tract dysfunctions. Currently, the compounds responsible for this activity have been identified, and their mechanism of action is known. Additionally, many more compounds were found in potato which are responsible for invoking various health-benefiting effects. This manuscript provides an overview of the data published on the production of potatoes and the accompanying PJ. First, the chemical characteristics of the protein and nonprotein fractions are described together with the conventional methods for the handling of this by-product. Second, novel technologies of PJ processing are presented with emphasis on the separation of protein and its hydrolysis, and various potential applications in food technology and biotechnology. Finally third, the medical potential of PJ is reviewed. This includes antimicrobial, antioxidant, anti-inflammatory, anticancer, antiobesity, antidiabetic, antihyperlipidemic, antihypertensive activities of various constituents of the juice. The wide range of potential applications and a vast spectrum of beneficial properties make PJ a substance well worth the attention of researchers and industry.