Polyhydroxybutyrate (PHB) is an attractive substitute for petrochemical plastic due to its similar properties, biocompatibility, and biodegradability. The cost of scaled-up PHB production inhibits its widespread usage. Intensive researches are growing to reduce costs and improve thermomechanical, physical, and processing properties of this green biopolymer. Among cheap substrates which are used for reducing total cost of PHB production, some C₁ carbon sources, e.g., methane, methanol, and CO₂ have received a great deal of attention due to their serious role in greenhouse problem. This article reviews the fundamentals of strategies for reducing PHA production and moves on to the applications of several cheap substrates with a special emphasis on methane, methanol, and CO₂. Also, some explanation for involved microorganisms including the hydrogen-oxidizing bacteria and methanotrophs, their history, culture condition, and nutritional requirements are given. After description of some important strains among the hydrogen-oxidizing and methanotrophic producers of PHB, the article is focused on limitations, threats, and opportunities for application and their future trends.

A new natural surface modified nanoclinoptilolite (NCP) was prepared and applied as an efficient catalyst for the cyclotrimerization of acetophenones to obtain 1,3,5-triarylbenzenes. The results showed that the efficiency of this catalytic system was enhanced due to the surface modification by hexadecyltrimethylammonium bromide (HDTMA-Br). This proposed protocol brings about significant economic and environmental advantages, such as operational simplicity, short reaction time, mild reaction conditions, good reaction yield, and high recyclability of the catalyst. Furthermore, the only side product of the reaction is water, which makes this methodology an environmentally friendly process.

Cyclotrimerization of ketones [(I) and (III)] leading to triarylbenzenes (II) or substituted benzenes like (IV), resp., is accomplished using nanozeolite surface modified by hexadecyltrimethylammonium bromide as recyclable catalyst.

For the reference "A viable antibiotic strategy against microbial contamination in biotechnological production of polyhydroxyalkanoates from surplus whey", Biomass Bioenerg 35:748-753, wrong author names have been listed.