This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
This article has been cited by other articles in PMC. Abstract Polyvinyl alcohol-degrading enzymes PVAases have a great potential in bio-desizing processes for its low environmental impact and low energy consumption. In this study, the effect of yeast extract on PVAases production was investigated.
A strategy of four-point yeast extract addition was developed and applied to maximize cell growth and PVAases production. As a result, the maximum dry cell weight achieved was 1.
Applying this strategy in a 7 L fermentor increased PVAases activity to 3. Three amino acids glycine, serine, and tyrosine in yeast extract play a central role in the production of PVAases.
These results suggest that the new strategy of four-point yeast extract addition could benefit PVAases production. Introduction Polyvinyl alcohol PVAa water-soluble synthetic polymer, has commercial applications in the adhesive, paper-coating, and textile industries [ 1 — 3 ].
The material is also of interest for packaging applications, such as bags for dyeing shops, Spectrophotometric determination of polyvinyl alcohol in paper coatings of household items, packaging of monodoses for powders and solid tablets, as well as for liquid concentrates, monodose packaging of chemicals for agriculture such as pesticides, and herbicides [ 4 ].
However, it is one of the major water pollutants in industrial wastewater, especially in textile factory wastewater. PVA is not easily decomposed in the environment.
Therefore, biological methods were investigated as a means of degrading PVA [ 5 — 8 ]. Researchers worldwide have focused their attention on new microbial isolates [ 910 ], purification of PVA-degrading enzymes PVAases [ 11 — 13 ], and PVA biodegradation mechanisms [ 13 ].
PVA has been found to be the only vinyl polymer that can be utilized by some bacteria as a carbon and energy source [ 1114 ]. There have been studies on the mechanisms of PVA biodegradation.
A different pathway for PVA degradation in Pseudomonas sp. Actually, the physiological characteristic of PVAases production by microorganisms in a submerged culture remains sketchy.
Our previous studies found that yeast extract is a rate-limiting factor for PVAases production [ 17 ]. Other work also relied on yeast extract as an energy source in culturing PVA-degrading bacteria, and the critical component has yet to be identified [ 1118 ].
Therefore, the intention of this work is to quantify the effect of yeast extract on the PVAases fermentation. This study uses an effective mixed culture screened by Chen et al. The observation that yeast extract stimulates cell growth and PVAases production prompted us to conduct further research on the components in yeast extract that are responsible for PVAase production.
To our knowledge, this is the first study that shows yeast extract to play a clear promoting role in the production of PVAases. Jiangsu Province, Chinaand the ability of the mixed culture in utilizing PVA was investigated in our previous study [ 9 ].
The pH was controlled automatically at 7. The reagents were purchased from Sangon Biotech Shanghai Co. Continuous yeast extract addition: Feeding of yeast extract started at 18 h of fermentation and stopped at 30 h.
Repeated yeast extract addition: Amino Acids Addition To find out which amino acids in yeast extract are the key ingredients for the production of PVAases, a mixture of 17 kinds of amino acids at concentrations identical to those found in yeast extract was added into the medium. One of the 17 amino acids was omitted each time.
Quantitative determination of PVA concentration in culture broth was carried out by spectrophotometric analysis after addition of boric acid and iodine solutions according to the procedure described by Finley [ 19 ]. The assay of PVAases activity was based on the methods described by Mori et al.
To understand the changes of amino acids in the cultivation media during the bacterial growth, the analysis of the amino acids composition in the media was done according to the methods described by Jae-Young et al.
Samples were analyzed with an amino acid analyzer Agilent, USA. All analyses were done in duplicates, and the average value was reported. Batch Fermentation in Fermentor Yeast extract contains abundant of vitamins, minerals, and amino acids, which are necessary for cell growth and PVAases synthesis [ 22 ].
Batch fermentation with yeast extract as nitrogen source in 7 L fermentor for PVAases production is shown in Figure 1. Cell growth stopped after 9 h of cultivation, and a maximum DCW of 1. After that, PVAases activity increased continually to 1. PVA was continuously degraded to 1. In our previous studies, it was found that the addition of yeast extract was not only advantageous to the growth of the mixed culture, but also propitious to PVAases synthesis [ 17 ].
With yeast extract as nitrogen source, we further investigate effects of different addition strategy of yeast extract on cell growth and the production of PVAases by feeding at a constant rate, single bolus addition, and repeated additions.Polyvinyl alcohol (PVA) is widely used in many applications, especially in the chemical, paper, and textile industries.
Because of its excellent water solubility, it is often used for thickening, emulsifying, paper-coating and warp sizing (Chou et al., , Zhang et al., ).
Spectrophotometric determination of polyvinyl alcohol in paper coatings. ADVERTISEMENT. Log In Register. Cart Spectrophotometric determination of polyvinyl alcohol in paper coatings.
Joseph H. Finley. Anal. Chem., , 33 (13), Spectrophotometric determination of highly functional organic acids with cis-dichlorobis(ethylenediamine. Selvol Polyvinyl Alcohol - A Versatile. Polymer for Specialty Coating Applications. APPLICATIONS. There are numerous coating applications where Selvol PVOH will provide.
enhanced performance. Additionally, Sekisui has a dedicated Applications Selvol Polyvinyl Alcohol - A Versatile Polymer for Specialty Coating Applications. 1. Introduction. Polyvinyl alcohol (PVA), a water-soluble synthetic polymer, has commercial applications in the adhesive, paper-coating, and textile industries [1–3].The material is also of interest for packaging applications, such as bags for dyeing shops, packaging of household items, packaging of monodoses for powders and solid tablets, as well as for liquid concentrates, monodose.
Abstract. PVA (Polyvinyl alcohol) is completely degraded and utilized by non-ubiquitous microorganisms as a sole source of carbon. PVA containing effluent treatments are not preferred because of high cost. An efficient biotreatment process for polyvinyl alcohol containing textile wastewater Sandip S.
Magdum J. H. Spectrophotometric determination of polyvinyl alcohol in paper coatings. Analytical Chemistry 33, – Ganidi, N., Tyrrel, S. & Cartmell, E. Anaerobic digestion foaming causes–a review.