Fundamental features of microbial cellulose utilization are examined at successively higher levels of aggregation encompassing the structure and composition of cellulosic biomass, taxonomic diversity, cellulase enzyme systems, molecular biology of cellulase enzymes, physiology of cellulolytic microorganisms, ecological aspects of cellulase-degrading communities, and rate-limiting factors in nature. The methodological basis for studying microbial cellulose utilization is considered relative to quantification of cells and enzymes in the presence of solid substrates as well as apparatus and analysis for cellulose-grown continuous cultures. Quantitative description of cellulose hydrolysis is addressed with respect to adsorption of cellulase enzymes, rates of enzymatic hydrolysis, bioenergetics of microbial cellulose utilization, kinetics of microbial cellulose utilization, and contrasting features compared to soluble substrate kinetics. A biological perspective on processing cellulosic biomass is presented, including features of pretreated substrates and alternative process configurations. Organism development is considered for "consolidated bioprocessing" (CBP), in which the production of cellulolytic enzymes, hydrolysis of biomass, and fermentation of resulting sugars to desired products occur in one step. Two organism development strategies for CBP are examined: (i) improve product yield and tolerance in microorganisms able to utilize cellulose, or (ii) express a heterologous system for cellulose hydrolysis and utilization in microorganisms that exhibit high product yield and tolerance. A concluding discussion identifies unresolved issues pertaining to microbial cellulose utilization, suggests approaches by which such issues might be resolved, and contrasts a microbially oriented cellulose hydrolysis paradigm to the more conventional enzymatically oriented paradigm in both fundamental and applied contexts.

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Microbial cellulose utilization: fundamentals and biotechnology.

Antibiotics have always been considered one of the wonder discoveries of the 20th century. This is true, but the real wonder is the rise of antibiotic resistance in hospitals, communities, and the environment concomitant with their use. The extraordinary genetic capacities of microbes have benefitted from man's overuse of antibiotics to exploit every source of resistance genes and every means of horizontal gene transmission to develop multiple mechanisms of resistance for each and every antibiotic introduced into practice clinically, agriculturally, or otherwise. This review presents the salient aspects of antibiotic resistance development over the past half-century, with the oft-restated conclusion that it is time to act. To achieve complete restitution of therapeutic applications of antibiotics, there is a need for more information on the role of environmental microbiomes in the rise of antibiotic resistance. In particular, creative approaches to the discovery of novel antibiotics and their expedited and controlled introduction to therapy are obligatory.

Origins and Evolution of Antibiotic Resistance

SUMMARY A collection of 267 strains, representing many of the principal biotypes among aerobic pseudomonads, has been subjected to detailed study, with particular emphasis on biochemical, physiological and nutritional characters. A total of 146 different organic compounds were tested for their ability to serve as sources of carbon and energy. Other characters that were studied included : production of extracellular hydrolases; nitrogen sources and growth factor requirements H-chemolithotrophy; denitrifying ability; pigment production; ability to accumulate poly-p-hydroxybutyrate as a cellular reserve material; biochemical mechanisms of aromatic ring cleavage; and nature of the aerobic electron transport system. The resultant data have revealed many hitherto unrecognized characters of taxonomic significance. As a consequence, it has become possible to recognize among the biotypes examined a limited number of species which can be readily and clearly distinguished from one another by multiple, unrelated phenotypic differences.

The Aerobic Pseudomonads a Taxonomic Study

The short history, specific features and future prospects of research of microbial metabolites, including antibiotics and other bioactive metabolites, are summarized. The microbial origin, diversity of producing species, functions and various bioactivities of metabolites, unique features of their chemical structures are discussed, mainly on the basis of statistical data. The possible numbers of metabolites may be discovered in the future, the problems of dereplication of newly isolated compounds as well as the new trends and prospects of the research are also discussed.

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Bioactive microbial metabolites.

The use of fossil fuels is now widely accepted as unsustainable due to depleting resources and the accumulation of greenhouse gases in the environment that have already exceeded the “dangerously high” threshold of 450 ppm CO2-e. To achieve environmental and economic sustainability, fuel production processes are required that are not only renewable, but also capable of sequestering atmospheric CO2. Currently, nearly all renewable energy sources (e.g. hydroelectric, solar, wind, tidal, geothermal) target the electricity market, while fuels make up a much larger share of the global energy demand (∼66%). Biofuels are therefore rapidly being developed. Second generation microalgal systems have the advantage that they can produce a wide range of feedstocks for the production of biodiesel, bioethanol, biomethane and biohydrogen. Biodiesel is currently produced from oil synthesized by conventional fuel crops that harvest the sun’s energy and store it as chemical energy. This presents a route for renewable and carbon-neutral fuel production. However, current supplies from oil crops and animal fats account for only approximately 0.3% of the current demand for transport fuels. Increasing biofuel production on arable land could have severe consequences for global food supply. In contrast, producing biodiesel from algae is widely regarded as one of the most efficient ways of generating biofuels and also appears to represent the only current renewable source of oil that could meet the global demand for transport fuels. The main advantages of second generation microalgal systems are that they: (1) Have a higher photon conversion efficiency (as evidenced by increased biomass yields per hectare): (2) Can be harvested batch-wise nearly all-year-round, providing a reliable and continuous supply of oil: (3) Can utilize salt and waste water streams, thereby greatly reducing freshwater use: (4) Can couple CO2-neutral fuel production with CO2 sequestration: (5) Produce non-toxic and highly biodegradable biofuels. Current limitations exist mainly in the harvesting process and in the supply of CO2 for high efficiency production. This review provides a brief overview of second generation biodiesel production systems using microalgae.

https://www.springer.com/cda/content/document/cda_downloaddocument/BioEnergyResearch_Second+Generation+Biofuels+High-Efficiency+Microalgae+for+Biodiesel+Production.pdf?SGWID=0-0-45-1347846-0

Second generation biofuels: high-efficiency microalgae for biodiesel production

For years the predominant application of microbial secondary metabolites was that of antibacterial, antifungal and antitumor chemotherapy. However, antibiotic activity represents a small part of the potential application of microbial secondary metabolites for the benefit of humankind. In this article, I shall point out applications other than as antibacterial, antifungal and antitumor agents. These include use against parasites, insects and weeds, as well as for animal and plant growth stimulation, immunosuppression, uterocontraction and many other pharmacological activities. The future will see further applications in various areas of pharmacology and agriculture, a development which is being catalyzed by the use of simple enzyme assays as prescreens prior to testing in intact animals or in the field.

Nonantibiotic Applications of Microbial Secondary Metabolites

Responsibilities in the Development of Biotechnology

Ivan Málek was a great scientist and an inspiration to Czech scientists and to microbiologists and biochemical engineers around the world. He brought Czech microbiology into the world of science and medicine. His devotion to continuous fermentation was recognized throughout the world. Despite the German occupation of Czechoslovakia during World War II, Málek worked on autovaccination therapy and was able to produce small amounts of penicillin, which was used to treat ill patients. He was a prolific writer of microbiological textbooks including Microbiology and Epidemiology (1946), Laboratory Methods for Bacteriological Diagnosis (1948), Fight of Modern Science Against Microorganisms (1951) and General Medical Microbiology (1953). It was in 1945 that, as a microbiologist and physician, he was appointed Lecturer at Charles University. A year after that, he went to Connaught Laboratories at the University of Toronto to study methods of penicillin production. This led to the establishment in 1949 of the first Czechoslovak penicillin factory in Roztoky u Prahy, a suburb of Prague. After his return from Canada, Málek lectured and taught more than 1,500 students studying medicine or nursing. In 1947, he established the country’s first school of medical laboratory technology. Málek became Associate Professor in 1948 and published his paper on variability of bacteria. In that same year, he taught and helped organize research at the new School of Medicine in Hradec Kralove. He also continued his work on continuous fermentation and returned to an early interest in mycobacteria. When the country formed an Academy of Sciences (ASCR) made up of research institutes in natural and social sciences in 1950, Málek was called upon to become the Director of the Central Institute of Biology in Prague and the Chairman of the Czechoslovak Society for Microbiology. He was soon elected to the ASCR and appointed as Chairman of the Central Institute of Biology. He helped found the journal Folia Microbiologica in 1956 and became the first Director of the Institute of Microbiology which was spun off from the Central Institute of Biology. This new institute, which soon became famous around the world for its first-rate research, was established in a new building in Krc, a district of Prague. He continued his work on continuous fermentation and established the importance of the ‘‘physiologic state’’ of microbiological populations. He was instrumental in the annual sending of ten or more Institute scientists to various laboratories in the USA and Western Europe. This is the way that many of us became familiar with excellent Czech scientists in our laboratories and those of our colleagues. Málek also arranged for foreign scientists to do their sabbatical leave research at the Institute of Microbiology. He was always willing to help the Institute’s scientists and technicians to overcome their difficult problems of life and existence. Quite often he served as an umbrella, kindly covering their more or less frequent acts of misconduct against an oppressive regime. Of great interest to Málek was the setting up of international meetings. After organizing the First International Symposium on the Continuous Cultivation of Microorganisms in Prague in 1958, the Proceedings were published by the ASCR and became well known around the world. This was followed by later Symposia in Prague in 1962, Porton Down, UK in 1966, Prague in 1968, and Oxford in A. L. Demain (&) Charles A. Dana Research Institute for Scientists Emeriti (RISE), Drew University, Madison, NJ 07940, USA e-mail: ademain@drew.edu

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Memories of a great man, Ivan Málek.

Streptomyces mannosidase, like the enzyme from other sources, is shown to require a divalent cation for enzyme activity. N-Ethylmaleimide pretreatment of enzyme-containing cells eliminated the requirement of aeration for enzyme activity. Methyl-α-D-mannoside was found to be a strong inhibitor of the hydrolysis of both p-nitrophenyl-α-D-mannoside and mannosidost reptomycin. The enzyme is bound at or near the surface of the cell and is inactivated by sonic oscillation. Small participate matter containing most of the activity can be released from the cells into water, such release being inhibited by phosphate, Tris, or sodium chloride.

Arnold L. Demain

Papers

Nonantibiotic Applications of Microbial Secondary Metabolites

Responsibilities in the Development of Biotechnology

Memories of a great man, Ivan Málek.

Location and action of Streptomyces griseus α‐D‐mannosidase, an antibiotic‐transforming enzyme

Creating Modern Industrial Microbiology