Polyhydroxyalkanoates and exopolysaccharides: An alternative for valuation of the co-production of microbial biopolymers.

Polyhydroxyalkanoates (PHAs) and exopolysaccharides (EPSs) belong to a class of abundant biopolymers produced by various fermenting microorganisms. These biocompounds have high value-added potential and can be produced concurrently. Co-production of PHAs and EPSs is a strategy employed by researchers to reduce costs associated with large-scale production. EPSs and PHAs are non-toxic, biocompatible, and biodegradable, making them suitable for various industrial sectors, including packaging and the medical and pharmaceutical industries. These biopolymers can be derived from agro-industrial residues, thus contributing to the bioeconomy by producing high-value-added products. This review investigates approaches for simultaneously synthesizing PHAs and EPSs using different carbon sources and microorganisms.

Co-production of levan with other high-value bioproducts: A review.

Levan is a homopolysaccharide of fructose that has both scientific and industrial importance, with various applications in health, pharmaceutical, cosmetic and food industries. Despite its broad spectrum of uses, there are only a limited number of commercial levan sources due to the high costs related to its production. To make production economically viable, efforts have been concentrated on the selection of levan-producing microorganisms, the genetic manipulation of new strains, and the use of inexpensive agro-industrial byproducts as substrates. Another efficient strategy involves the concomitant synthesis of other products with high market value and as such, the successful co-production of levan was demonstrated with fructooligosaccharides, ethanol, sorbitol, poly-ε-lysine, poly-γ-glutamic acid and polyhydroxyalkanoates. This paper offers a systematic review of important aspects regarding recent strategies involving the simultaneous synthesis of levan and other bioproducts of aggregate value reported to date and discusses the challenges and opportunities for its large-scale production and applications.

2,6-Anhydro-1,3-di-O-benzyl-d-mannitol.

In the title compound, C(20)H(24)O(5), the six-membered pyran-ose ring adopts a chair conformation. The dihedral angle between the planes of the phenyl groups of the benzyl substituents is 63.1°. Two types of inter-molecular O-H⋯O hydrogen bonds lead to the formation of infinite chains along the b axis. Only weak C-H⋯O contacts exist between neighboring chains.

Levan-based nanostructured systems: An overview.

Bacterial levan is a fructose homopolymer that offers great potential in biotechnological applications due to biocompatibility, biodegradability and non-toxicity. This biopolymer possesses diverse multifunctional features, which translates into a wide range of applicability, including in industry, consumer products, pharmaceuticals and biomedicine. Extensive research has identified great potential for its exploitation in human health. In addition, nanostructured systems have provided significant advances in the area of health, mainly with respect to disease diagnosis and treatment. While the functional properties of these natural polysaccharide-based polymers are desirable in these systems, research in this area has been limited to few natural polymers, such as chitosan, alginate and dextran, which obscures the true potential of levan in the production of nanostructured systems for biotechnological and medical applications. The present review considers the latest research in the field to focus on the use of levan as a promising biopolymer for the development of nanomaterials.