Abstract: Copolymers of lactic and glycolic acids are being developed by researchers at Battelle and elsewhere as renewable-resource plastics. Other uses include matrices for controlled release of drugs and pesticides as well as in prosthetic devices. In contrast to conventional plastics, lactic acid polymers are biodegradable, and after several months exposure to moisture, these materials convert back to natural harmless products. The properties of lactic acid polymers are examined.

Abstract: The biodegradation of alcohol ethoxylates (AE) and alkylphenol ethoxylates (APE) is reviewed. Biodegradation test methods, ranging from laboratory tests to full-scale waste treatment plant studies are described for these surfactants. A comparison is made between primary and ultimate biodegradability criteria and the limitations of the various analytical methods used in these determinations are discussed. The most recently published data suggest sewage bacteria degrade AE by a mechanism which is different from that by which APE degrades. The use of radiolabeled surfactants to elicit more detailed information about the biodegradation mechanisms of AE is described. The role of biodegradation on the impact of surfactants released to the environment is assessed, and future environmental concerns for nonionics are considered.

Abstract: : Biodegradation of the explosive hexahydro-1,3,5-trinitro-1,3,5- triazine (RDX) occurs under anaerobic conditions to yield a number of products including: hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine, hexahydro-1,3- dinitroso-5-nitro-1,3,5-triazine, hexahydro-1,3,5-trinitroso-1,3,5-triazine, hydrazine, 1,1-dimethylhydrazine, 1,2-dimethylhydrazine, formaldehyde, and methanol. A scheme for the biodegradation is proposed which proceeds via successive reduction of the nitro groups to a point where destabilization and fragmentation of the ring occurs. The non-cyclic degradation products arise via subsequent reduction and rearrangement reactions of the fragments.

Abstract: Lignin ranks second only to cellulose as the most abundant organic compound on earth. It is also the major solid component of spent sulfite liquor produced by the pulp and paper industry. As a result of chemical pulping, a quantity of dissolved materials roughly equal to the amount of paper products is produced as waste products in the effluent [1]. The polluting potential of these effluents is well known. Studies on the possibility of producing chemical feedstocks from these pulping streams may develop into technological advancements in the abatement of pollution as well as economic recovery of a renewable resource. Any chemical feedstock production from lignin would transfer the demands upon non-renewable petroleum resources to manageable renewable natural resources. Degradation of lignin by microorganisms is hindered by the unique structure of this poly-phenolic polymer. The polymer is composed of phenolic units bound by a variety of carbon-carbon and carbon-oxygen linkages which prohibit the type of attack noticed on the more readily hydrolyzable polymers found in nature [2]. The long periods of time required for degradation by the white-rot fungi prevent any immediate industrial application of microbial treatment. Recent technological advances involving 14C-labeled synthetic lignins have produced valuable information concerning total degradation of lignin to 14CO2 [3, 4]. This area of research, however, reveals little about the nature of any intermediate breakdown products which could be utilized as chemical feedstocks. Recently, a macromolecular mechanism for degradation of a lignosulfonate preparation by the basidiomycete Fomes annosus was described by Haars and Huttermann [5]. They detected small-molecular-weight phenol and phenolether products after incubation for 4, 10 and 20 days. There was an absence, however, of any intermediatemolecular-weight compounds. From these results they proposed an exo-degradation mechanism due to the inability of the organism to split the lignin molecule into intermediate-size fragments. Our investigations into lignin degradation by yeast demonstrate a different mechanism of attack. Rouge, Louisiana

Abstract: A continuous cultivation apparatus was constructed in order to improve the existing biological treatments for waste dye–liquor. The cleaning effect by Pseudomonas pseudomallei 13NA, an azo–assimilating bacteria, was examined. Using p–aminoazobenzene as a typical component of waste dye–liquor, it was found that the bacteria effectively removed it by biological degradation. For example, 80% of 10 ppm p–aminoazobenzene was removed by a three–stage continuous treatment.

Abstract: In this work we discuss the aerobic biodegradation of sodium sulfite liquor of (NaSSL) and sodium lignosulfonate (NaLS) in a firwood sulfite waste liquor by a mixed culture of microorganisms consisting of two Trichosporon yeasts and bacteria in the Arthrobacter (two species), Pseudomonas and Chromabacterium genera. Under established process parameters, the NaSSL was biodegradated in one or two stages by mixed cultures. The kinetics in each stage was studied. The optimal ratio of NaLS and sugars in the substrate for the growth of mixed culture was determined. The growth of the monocultures of the bacteria on the NaLS and the growth of the yeasts as monocultures on the NaSSL substrate were examined. UV absorption and IR spectra were employed as analytical methods to follow the microbial degradation of NaLS. The aim of this research was to study the biodegradation process and kinetics and to remove by means of mixed culture the maximum amount of organic matter from NaSSL.

Abstract: A model system is used to study the reaction engineering fundamentals of the biological waste gas scrubbing process, and some kinetic measurements of the biodegradation of pollutants dissolved in the absorbent are presented.

Abstract: : Biodegradation of many of the components of Air Force fuels does occur, although most studies have been done under laboratory conditions, and the extrapolation of the findings to natural rates of biodegradation is premature. Many factors affect biodegradation rates, including the nature and concentration of the specific hydrocarbon compound, the species of bacteria present and their quantity, and environmental factors such as nutrient availability, temperature, and oxygen concentrations. Initial concerns should be first, the determination of the importance of biodegradation relative to other loss factors such as volatilization and sediment sorption, and second, the determination of the ultimate fate of recalcitrant compounds and their metabolites. (Author)

Abstract: By oxidizing treatment of waste waters, which are normally scarcely accessible to biodegradation, the molecular structure of the compounds can be altered in such a way that biodegradation becomes possible. It is shown by the example of two types of waste water how rapidly the elimination of persistent substances proceeds by biological treatment after preceding ozonization. A gradual improvement of the elimination rate can often be achieved by combining ozone treatment with adsorption procedures.

Abstract: PURPOSE: To prepare the titled composition, economically, by mixing a crude sugar fatty acid ester containing soaps and a sugars with a specific organic solvent, water, and an acid sufficient to convert the soap to fatty acid, subjecting the mixture to the liquid-liquid extraction in the presence of a salt, and separating and concentrating the organic solvent phase. CONSTITUTION: (A) A crude sugar fatty acid ester containing at least (i) a sugar fatty acid ester, esp. sucross fatty acid ester, (ii) a soap, esp. a fatty acid alkali metal salt and (iii) a sugar, esp. sucrose, is mixed with (B) an organic solvent selected from esters, ketones, alcohols, and halogenated hydrocarbons, (C) water, and (D) an acid sufficient to convert the soap to the fatty acid, and is extracted to the liquid phase taking advantage of the effect of the salt. The extract is separated into the organic solvent phase and the aqueous phase, and the organic solvent phase is evaporated and concentrated to obtain the objective composition useful as a surface-active agent having excellent biodegradability and safety, economically, easily, in high yield and purity. COPYRIGHT: (C)1982,JPO&Japio

Abstract: Biotransformation and biodegradation rate constants were determined for naphthalene, lindane, and phenol in water samples from three different sources. Rate constants produced from monitoring disappearance of the parent chemical (biotransformation) were compared to those obtained from mineralization of the chemical (ultimate biodegradation) by ¹⁴CO₂ evolution as well as acidification of the residual ¹⁴C-labeled compound (primary biodegradation). Rate constants were statistically different for the three chemicals. The water source affected the rate constants. When biomass measurements of the waters were considered and second-order rate constants were derived, there was no statistical evidence that this parameter gave a reliable rate constant statistic that could be useful in predicting the fate of any of naphthalene, lindane, and phenol in these waters.

Abstract: A process for converting biodegradable carbon-containing materials into substances containing a significant proportion of methylene groups, which process comprises subjecting the biodegradable carbon-containing materials to bacterial action in a container under conditions of temperature suitable for the bacterial flora present to thrive, of pressure such that any evolved gasses are retained in contact with the carbon-containing materials, of volume such that the free space in the container is minimised, and in the presence of at least sufficient water to maintain the bacterial flora alive.

Abstract: The persistence of synthetic herbicides such as 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) and its release in massive amounts as a herbicide (Agent Orange) have created toxicological problems in many countries. In nature, 2,4,5-T is slowly degraded by cooxidation and is not utilized as a sole source of carbon and energy. The technique of plasmid-assisted molecular breeding has led to the development of bacterial strains capable of totally degrading 2,4,5-T by using it as their sole source of carbon at high concentrations (greater than 1 mg/ml). Spectrophotometry and gas chromatography reveal various intermediates during growth of the culture with 2,4,5-T.

Abstract: 5 White-Rot Basidiomycetes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 5.1 Mineralization of 14C-Labeled Lignins . . . . . . . . . . . . . . . . . . . . . . . 141 5.2 Ligninolytic Enzymes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 5.2.1 Lignin Peroxidase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 5.2.2 Manganese Peroxidase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151 5.2.3 Laccase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 5.2.4 Other Enzymes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161

Abstract: The decomposition of pure hydrocarbons in soils depends essentially on the intrinsic biological activity of the soils. Seasonal variations were observed, but other environmental factors, such as acidity, were more important. In non-acid soils, the structure of the hydrocarbons was secondary, whereas in acid soils, the rate of decomposition was much slower and depended on their chain length. The difference was reflected, in characteristic soils, in the natural distribution of the hydrocarbons, which originate predominantly from plant decay. Two acid soils, supplemented with ferric hydroxide, were incubated for 16 weeks at 28°C and their hydrocarbon fraction analyzed. Iron enrichment did not lead to complete biodegradation but rather to stimulation of the biooxidation of unbound hydrocarbons and to disppearance of the chain length discrimination. Conversely, the bound alkanes were stable towards microbial activity, with only the amounts of short chain hydrocarbons being slightly reduced.

Abstract: Considerable interest has been focused on the synthesis of biodegradable polymers in specialized applications such as controlled release drug formulations, insecticide and pesticide carriers, and nontoxic surgical implant materials. For many agricultural and ecological uses it is desirable to have a biodegradable polymer that will degrade in a physiological environment or by microbial action in the soil.