Single-cell proteins

Both photosynthetic and nonphotosynthetic microorganisms, grown on various carbon and energy sources, are used in fermentation processes for the production of single-cell proteins. Commercial-scale production has been limited to two algal processes, one bacterial process, and several yeast and fungal processes. High capital and operating costs and the need for extensive nutritional and toxicological assessments have limited the development and commercialization of new processes. Any increase in commercial-scale production appears to be limited to those regions of the world where low-cost carbon and energy sources are available and conventional animal feedstuff proteins, such as soybean meal or fish meal, are in short supply.     

Mutants of Rhizobium japonicum with Increased Hydrogenase Activity

Some strains of Rhizobium japonicum can use hydrogen as an energy source for growth under microaerophilic conditions. Mutant strains have been selected that use hydrogen in the presence of high partial pressures of oxygen. The mutants contain more hydrogenase than the parent strain, both as free-living cells and as bacteroids in nitrogen-fixing soybean root nodules.     

A fossil noctuid moth egg from the late cretaceous of eastern north america

A moth egg assignable to the family Noctuidae (Lepidoptera) is described from 75-million-year-old sediments from Martha's Vineyard, Massachusetts. This sample, which extends the fossil record of this farnily and modern heteroneuran moths back to the Cretaceous, may provide insight into the coevolution of moths and flowering plants, as well as have implications for the evolution of bats.     

Rates of evolution: effects of time and temporal scaling

Rates of morphological evolution documented in laboratory selection experiments, historical colonization events, and the fossil record are inversely related to the interval of time over which they are measured. This inverse relationship is an artifact of comparing a narrow range of morphological variation over a wide range of time intervals, and it is also a product of time averaging. Rates measured over different intervals of time must be scaled against interval length before they can be compared.