Hypochlorite digestion

The method of pure polymer recovery from the biomass prior to characterization can influence the molecular weight of the polymer significantly. Extraction of PHB-bacterial cells with organic solvents yields polymers with higher molecular weight compared to sodium hypochorite treatment [44-46]. Pretreatment of the biomass with a surfactant prior to hypochlorite digestion... 

Fig. la-c. Sensitivity analysis on the effect of P(3HB) content and productivity on the production cost of P(3HB) at different yield and production scale. Surfactant-hypochlorite digestion method was used for the recovery of P(3HB) (reproduced from [29] with permission)... 

The common chemical methods for extraction of PHB are solvent extraction, chemical digestion using sodium hypochlorite, sodium hypochlorite and chloroform, surfactants, surfactant hypochlorite digestion, surfactant chelate digestion, chelate hydrogen peroxide treatment, selective dissolution of nonpolymer cell mass by proton etc. 

Another method for extraction of PHB is by using sodium hypochlorite digestion method. With this method, 86% purity was observed with R. eutropha and 93% purity with E. coli. One of the major drawbacks of this method is that it causes degradation of PHB resulting in 50% reduction in molecular weight. 

Berger E, Ramsay BA, Ramsay JA, Chavarie C. PHB recovery by hypochlorite digestion of non-PHB Biomass. Biotechnol Tech 1989 3 227-32. 

Surfactant-Hypochlorite Digestion. The surfactant-hypochlorite digestion method is a cost-effective process with a limited effect on PHA degradation. It has been evaluated that US 5.58/kg of P(3HB) is produced for the annual production of 2850 tonnes of purified P(3HB) using the surfactant-hypochlorite digestion method from C. necator. However, it has a lower price compared to the chloroform-hypochlorite system. The cost of P(3HB) declined to US 4.75/kg due to an increase in the production scale to one million tonnes per year. ... 

Sodium hypochlorite was first used by Williamson and Wilkinson (1958) to isolate PHB granules from Bacillus cereus. However, sodium hypochlorite digestion of NPCM resulted in the lysis of cells without affecting the PHB. Sodium hypochlorite purification method was affecting the sudanophilic properties and molecular weight of the polymer granules. 

Sayyed, R. Z., Gangurde, N. S., and Chincholkar, S. B. (2009). Hypochlorite digestion method for efficient recovery of PHB from A. faecalis. Indian Journal ofMicrobiology 49(3), 230-232. 

Rayner, P., Safety Digest Univ. Safety Assoc., 1991, 40, 14 A methyl but-3-enylimidate ester hydrochloride, was charged to a tenfold excess of stirred 14% hypochlorite solution cooled in ice. After 50 min the flask was removed to replenish the ice. Shortly after returning the flask to the icebath a violent explosion shattered both flask and icebath. This was attributed to thermal runaway (although available energy is scarcely sufficient to boil the water in the flask). It seems more likely that trichloroamine was generated by the excess hypochlorite, settled when removed from the magnetic stirrer, and detonated from friction when this restarted. The reaction is said to have been performed many times previously without incident. 

A 4.37-mg sample of protein was chemically digested to convert its nitrogen into ammonia and then diluted to 100.0 mL. Then 10.0 mL of the solution were placed in a 50-mL volumetric flask and treated with 5 mL of phenol solution plus 2 mL of sodium hypochlorite solution. The sample was diluted to 50.0 mL, and the absorbance at 625 nm was measured in a 1.00-cm cuvet after 30 min. For reference, a standard solution was prepared from... 

Formed when protoxide of bismuth is fused with hydrate of potash, or when it is digested in a solution of chloride (hypochlorite) of soda. It is a heavy brorm powder, of a neutral character. 

The gross conformation of acetylated lysozyme is similar to that of the native enzyme, as has been shown by measurement of enzymic activity and fluorescence properties.However, protease digestion, t-butyl hypochlorite modification, and thermal denaturation experiments on native, acetylated, and guanidinated lysozymes have demonstrated that acetylation causes a small but significant shift of the (native denatured) transition to the right. It was concluded that the charge balance in the protein plays an important part in maintaining conformation. 

A latex of poly(/3-hydroxyoctanoate) can be obtained from the bacterium Pseudomonas oleovorans grown on sodium octanoate at a high cell density (22). In the course of purification sodium hypochlorite was used. It was observed that latex stabilization occurred spontaneously due to the persistence around the polymer granules of the murein sacculus, which envelopes the bacterial ceU. It was shown that the optimal conditions for the bacteria digestion correspond to a sodium h ochlorite concentration of 21-26 mmolg. ... 

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