Microbial bio-based plastics from olive-mill wastewater: Generation and properties of polyhydroxyalkanoates from mixed cultures in a two-stage pilot scale system.

The operational efficiency of a two stage pilot scale system for polyhydroxyalkanoates (PHAs) production from three phase olive oil mill wastewater (OMW) was investigated in this study. A mixed anaerobic, acidogenic culture derived from a municipal wastewater treatment plant, was used in the first stage, aiming to the acidification of OMW. The effluent of the first bioreactor that was operated in continuous mode, was collected in a sedimentation tank in which partial removal of the suspended solids was taking place, and was then forwarded to an aerobic reactor, operated in sequential batch mode under nutrient limitation. In the second stage an enriched culture of Pseudomonas sp. was used as initial inoculum for the production of PHAs from the acidified waste. Clarification of the acidified waste, using aluminium sulphate which causes flocculation and precipitation of solids, was also performed, and its effect on the composition of the acidified waste as well as on the yields and properties of PHAs was investigated. It was shown that clarification had no significant qualitative or quantitative effect on the primary carbon sources, i.e. short chain fatty acids and residual sugars, but only on the values of total suspended solids and total chemical oxygen demand of the acidified waste. The type and thermal characteristics of the produced PHAs were also similar for both types of feed. However the clarification of the waste seemed to have a positive impact on final PHAs yield, measured as gPHAs/100g of VSS, which reached up to 25%. Analysis of the final products via nuclear magnetic resonance spectroscopy revealed the existence of 3-hydroxybutyrate (3HB) and 3-hydroxyoctanoate (HO) units, leading to the conclusion that the polymer could be either a blend of P3HB and P3HO homopolymers or/and the 3HB-co-3HO co-polymer, an unusual polymer occurring in nature with advanced properties.

[Indices of a threatened pregnancy in the first trimester]. / Prouchvaniia na niakoi pokazateli pri narushena bremennost v purviia trimestur.

Studies were carried out on 167 pregnant women, divided into 4 groups in accordance with the values of human chorionic gonadotropin (HCH). Fetal death was established by ultrasound in 41 of the pregnant women including all cases with HCG under 5000 IU, but it was also found in 19.18% of women with values of HCG over 10,000 IU. Pregnancy advanced unfavourably in other 16 pregnant women of altogether in 34.13%. Prognosis was unfavourable in the presence of decidual hematoma. The gestational sac was enlarged on the average. 1.3 mm per day in normal development. Treatment was made in two groups: with hormones, spasmolytics and vitamins and only with spasmolytics and vitamins. The results showed that progesterone preparations, used singly or in combination with estradiol, did not improve the results.