ABSTRACT Polyhydroxyalkanoates (PHAs) have attracted major industrial interest as alternatives to conventional plastics. They are produced by several bacteria as cytoplasmic inclusions when nutrients are in limited supply. Among the many factors influencing bacterial growth, the effect of temperature on both specific growth rates and growth yields in terms of carbon source intake is of considerable interest. This study aimed to evaluate the influence of the bacterium Burkholderia sacchari LFM 101 on growth and PHA production, using glucose, sucrose or glycerol as a carbon source, at 30 and 35 °C. The results showed that B. sacchari cultured with glucose at 35 °C presented both higher productivity and polymer yield in dried cell mass. There were no differences in growth rates (μmax) in sucrose and glucose. The growth conditions studied were not favorable to glycerol consumption due to limitations in the energy supply from glycerol.

In recent years, several studies have been developed in Brazil to produce biodegradable materials. A particular family of bacterial polymers, the polyhydroxyalkanoates (PHA), has received special attention. PHAs are thermoplastic, biodegradable, biocompatible, are synthesised from renewable resources and can substitute petrochemical plastics in some applications. Different aspects have been focused to increase productivity and to reduce the cost of PHA production: bacterial improvement, use of industrial by-products as raw material, bioreactor design, process operation strategies, downstream process, mathematical modelling, polymer characterisation, application and biodegradability of blends. A production process was transferred to industry and studies to produce new PHA by controlling monomer composition are in progress. All these aspects are presented in this review.