— Bacterial spores contained in sugarcane bagasse were subjected to various combinations of heat exposure and alkali concentration and the rate of destruction determined for each set of conditions. A series of survival, thermal death time and alkaline destruction curves revealed a different mode of death by heat exposure than alkali treatment. Addition of alkali into the heating menstruum caused the death rates of bacterial spores to be much greater than with heat alone at a given temperature. Exposure of the spores to a temperature of 75°C for 130 min was required to reduce the spore population by 90% with heat treatment alone. Incorporation of a 1% NaOH solution into the heating menstruum effected the same degree of destruction of the spores within a 2 min period at the same temperature. From a series of thermal destruction and alkaline destruction curves, an empirical equation expressing the relationship between the death rate of bacterial spores, and the intensity of temperature and the concentration of alkali was established. The equation reveals that the death rate of bacterial spores is affected in an exponential manner by temperature and in a direct relationship by alkali concentration. Using the equation, sterilization time for various combinations of temperature and alkali concentration was determined and the overall correlation index between the experimental data and computed value was 0.877.

The shortage of oil and natural gas will soon be reflected in shortages and spiraling prices for polymers based on hydrocarbons.Cellulose derivatives, which will be their replacement, are currently not competitive in many applications. This paper presents data on the fundamental relationships between several derivatives and their solubility characteristics.It also discuss' the design of reactors needed to produce the polymers most economically.

No abstract

Production of protein and volatile fatty acids by anaerobic digestion of blackstrap molasses was investigated. This protein may have potential as a feed for animals (and, we hope, for humans) in the near future. Volatile fatty acids can be further fermented to produce methane. Fermentation of molasses byEubacterium ruminantium was studied in a chemostat at a constant temperature of 37 C. This study focused on kinetics of growth of the pure culture. The maximum rate of protein production of about 0.326 g/l/hr was obtained when the pH and retention times were 6.2 and between 5 and 7 hrs, respectively. Average cell yield was 12.6% and carbohydrate conversion was 82 to 99%. Volatile fatty acids also were produced, with acetic acid and n‐butyric acid being the predominant products. Two different kinetic models were used to fit the experimental data. The kinetic parameters obtained for the Monod model were: μmax=0.207 (1/hr); ks=0.165 g/l.

The effects of chemical, physical, and enzymatic treatments of rice straw and sugarcane bagasse on the microbial digestibility of cellulose have been investigated. Treatment with 4% NaOH for 15 min at 100 C increased the digestibility of cellulose from 29.4 to 73%. Treatment with 5.2% NH 3 could increase digestibility to 57.0% Treatments with sulfuric acid and crude cellulase preparation solubilized cellulose but did not increase the digestibility. Grinding or high-pressure cooking of the substrate had little effect on increasing the digestibility of cellulosic substrates by the Cellulomonas species.