Whey Lactose as a Raw Material for Microbial Production of Biodegradable Polyesters

Fossil fuel technologie

Revijalni prikaz suvremene biotehnološke sinteze polimera

The industrial implementation of cost- and eco-efficient production of bio-based polymeric materials such as polyhydroxyalkanoates (PHAs) or polylactic acid (PLA) requires the comprehension of all process steps. The article at hand provides an insight into recent advances in allocation, pretreatment and utilization of raw materials available for biopolymer production in different areas of the world. Further, the high potential and risks of applying continuous process conduction in comparison with batch and fed-batch fermentation mode are elucidated. It is shown that the process design for continuous PHA production strongly depends on the kinetic characteristics for growth and product formation of the applied production strain. In addition, the triggering of the biopolymer properties by fine-tuning of the polyester composition during biosynthesis is demonstrated. Here, the impact of certain process parameters like the partial oxygen tension on the intracellular metabolic fluxes and the supplementation of cosubstrates on the polyester composition are discussed. In addition, such specialists among microbes are presented that possess the metabolic prerequisites to accumulate high-quality copolyesters merely from cheap unrelated carbon sources without the necessity for supplying expensive cosubstrates. In the field of downstream processing, sustainable methods for product isolation during biopolymer production that do not have a negative influence on the environment are presented.Industrijska proizvodnja isplativih i ekoloških biopolimernih materijala, poput polihidroksialkanoata ili polimliječne kiseline, zahtijeva razumijevanje svih faza procesa. Stoga su u radu navedeni najnoviji postupci alokacije i prethodne obrade, te načini uporabe sirovina za proizvodnju polimera u različitim dijelovima svijeta. Zatim su procijenjeni mogućnost i rizik primjene kontinuiranog procesa proizvodnje, u usporedbi sa šaržnom fermentacijom s pritokom supstrata ili bez njega. Pokazalo se da dizajn procesa kontinuirane proizvodnje polihidroksialkanoata uvelike ovisi o kinetici rasta proizvodnoga soja i formiranju produkta. Osim toga, preciznim se podešavanjem sastava poliestera potiče oblikovanje različitih biopolimera. Utvrđeno je da djelomična zasićenost kisikom utječe na intracelularne tokove a dodatak kosupstrata na sastav poliestera. U radu su navedene neke vrste mikroorganizama koje bez dodatka skupih kosupstrata mogu akumulirati visokokvalitetne kopoliestere iz jeftinih izvora ugljika. Također su prikazane održive metode izolacije biopolimera koje nemaju negativan utjecaj na okoliš

Protective intraoperative ventilation with higher versus lower levels of positive end-expiratory pressure in obese patients (PROBESE): study protocol for a randomized controlled trial

Background: Postoperative pulmonary complications (PPCs) increase the morbidity and mortality of surgery in obese patients. High levels of positive end-expiratory pressure (PEEP) with lung recruitment maneuvers may improve intraoperative respiratory function, but they can also compromise hemodynamics, and the effects on PPCs are uncertain. We hypothesized that intraoperative mechanical ventilation using high PEEP with periodic recruitment maneuvers, as compared with low PEEP without recruitment maneuvers, prevents PPCs in obese patients. Methods/design The PRotective Ventilation with Higher versus Lower PEEP during General Anesthesia for Surgery in OBESE Patients (PROBESE) study is a multicenter, two-arm, international randomized controlled trial. In total, 2013 obese patients with body mass index ≥35 kg/m2 scheduled for at least 2 h of surgery under general anesthesia and at intermediate to high risk for PPCs will be included. Patients are ventilated intraoperatively with a low tidal volume of 7 ml/kg (predicted body weight) and randomly assigned to PEEP of 12 cmH2O with lung recruitment maneuvers (high PEEP) or PEEP of 4 cmH2O without recruitment maneuvers (low PEEP). The occurrence of PPCs will be recorded as collapsed composite of single adverse pulmonary events and represents the primary endpoint. Discussion To our knowledge, the PROBESE trial is the first multicenter, international randomized controlled trial to compare the effects of two different levels of intraoperative PEEP during protective low tidal volume ventilation on PPCs in obese patients. The results of the PROBESE trial will support anesthesiologists in their decision to choose a certain PEEP level during general anesthesia for surgery in obese patients in an attempt to prevent PPCs. Trial registration ClinicalTrials.gov identifier: NCT02148692. Registered on 23 May 2014; last updated 7 June 2016. Electronic supplementary material The online version of this article (doi:10.1186/s13063-017-1929-0) contains supplementary material, which is available to authorized users

Modern Biotechnological Polymer Synthesis: A Review

The industrial implementation of cost- and eco-efficient production of bio-based polymeric materials such as polyhydroxyalkanoates (PHAs) or polylactic acid (PLA) requires the comprehension of all process steps. The article at hand provides an insight into recent advances in allocation, pretreatment and utilization of raw materials available for biopolymer production in different areas of the world. Further, the high potential and risks of applying continuous process conduction in comparison with batch and fed-batch fermentation mode are elucidated. It is shown that the process design for continuous PHA production strongly depends on the kinetic characteristics for growth and product formation of the applied production strain. In addition, the triggering of the biopolymer properties by fine-tuning of the polyester composition during biosynthesis is demonstrated. Here, the impact of certain process parameters like the partial oxygen tension on the intracellular metabolic fluxes and the supplementation of cosubstrates on the polyester composition are discussed. In addition, such specialists among microbes are presented that possess the metabolic prerequisites to accumulate high-quality copolyesters merely from cheap unrelated carbon sources without the necessity for supplying expensive cosubstrates. In the field of downstream processing, sustainable methods for product isolation during biopolymer production that do not have a negative influence on the environment are presented

Whey Lactose as a Raw Material for Microbial Production of Biodegradable Polyesters

Whey, a by-product of diary and cheese industry, constitutes the watery portion after the separation of fat and caseins from whole milk. Cheese whey is a surplus material produced in volumes almost equal to the milk processed in cheese manufactories, therefore its disposal as a waste causes serious pollution problems in the surrounding environment where it\ub4s discarded. This is due to its enormous biochemical oxygen demand that is mainly caused by its high lactose content; as a consequence a large amount of industrial capital is requested for whey disposal. During the last years, the amounts of whey increased to such an extent that they cannot be simply used as animal feed as the most common application. To overcome these problems a sustainable alternative is to upgrade whey and its derivates to a resource for many value added industrial products, making whey not only a waste but also a valuable resource. The article presents a future-oriented, alternative strategy to use surplus whey, namely its upgrading to the role of a raw material for cost-efficient production of polyhydroxyalkanoate (PHA) biopolyesters. PHAs are a group of bio-based, bio-compatible and compostable bio-plastics of increasing significance for numerous industrial applications. Data for PHA production from whey on different production scales and techniques by various microbial species are compared and embedded in the entire scientific field of biopolymers. The review shows how the smart solution of an industrial waste disposal problem can be combined with enhanced cost efficiency in production of \u201cgreen plastics\u201d

Chapter Whey Lactose as a Raw Material for Microbial Production of Biodegradable Polyesters

Fossil fuel technologie

Effect of Intraoperative High Positive End-Expiratory Pressure (PEEP) With Recruitment Maneuvers vs Low PEEP on Postoperative Pulmonary Complications in Obese Patients: A Randomized Clinical Trial (vol 321, pg 2292, 2019)

status: publishe