First, the role of microbiology in solving the five major crises facing mankind
As we all know, mankind is facing various crises, such as food crisis, energy shortage, resource shortage, ecological deterioration, human bombing and so on.
After entering the 2 1 century, mankind will encounter a series of new problems arising from the transition from the era of using limited mineral resources to the era of using unlimited biological resources.
Microbial cell is not only a life system with large specific surface area, strong biochemical transformation ability and rapid self-replication, but also has the diversity of species, heredity, metabolism and ecological types, which makes it play an irreplaceable and unique role in solving various crises faced by mankind.
Now described as follows.
Microbes and food
Grain production is a major event for the survival of all mankind.
Microbes can play an important role in improving soil fertility, improving crop characters (such as constructing nitrogen-fixing plants), promoting grain yield, preventing grain pests and diseases, preventing grain from mildew and deterioration, and transforming surplus grain into sugar, single cell protein, various beverages and condiments.
Microbes and energy
At present, the problem of fossil energy depletion is seriously puzzling all countries in the world.
Microorganisms have their unique advantages in energy production: ① Converting cellulose, which is extremely rich in nature, into ethanol.
It is estimated that the annual output of plant straw in China is as high as 500-600 million tons. If 10% is hydrolyzed and fermented, 7-8 million tons of fuel alcohol can be produced, and the remaining residues can still be used as feed and fertilizer to ensure the normal supply of potassium and phosphorus in the soil.
At present, it is found that thermophilic anaerobic bacteria such as Closiridiumthermocellum can directly decompose cellulose to produce ethanol.
(2) Using methanogenic bacteria to convert the most abundant renewable resource biomass in nature into methane.
This is a major strategic move that benefits the country and the people, the ecology and future generations.
③ Using microorganisms such as photosynthetic bacteria, cyanobacteria or anaerobic Fusobacterium to produce "clean energy"-hydrogen.
④ Gas production or its metabolites are fermented by microorganisms to improve oil recovery.
⑤ Study microbial batteries and make them practical.
(3) Microorganisms and resources
Microorganisms can transform the inexhaustible renewable resources such as cellulose on the earth into various industrial raw materials such as chemical industry, light industry and pharmacy.
Besides the traditional ethanol, acetone, butanol, acetic acid, glycerol, isopropanol, methyl ethyl ketone, citric acid, lactic acid, malic acid, fumaric acid and methylene succinic acid, these products can also produce salicylic acid, aconitic acid, acrylic acid, adipic acid, acrylamide, sebacic acid, long-chain fatty acids, long-chain diols, 2,3-butanediol, γ -linolenic acid oil and polyhydroxybutyrate.
Because fermentation engineering has many advantages such as many kinds of metabolites, wide sources of raw materials, low energy consumption, high economic benefits and less environmental pollution, it will gradually replace the chemical industry that needs high temperature, high pressure, high energy consumption and serious "three wastes".
Microorganisms also play a unique role in the development and utilization of metal mineral resources.
The bacterial leaching technology mentioned in chapter 9 can continuously dissolve and extract more than ten kinds of metals such as copper, nickel and uranium contained in long-term abandoned low-grade ores, tailings and slag, and become a new important resource.
(d) Microbes and environmental protection
There are many places where microorganisms can be used in environmental protection: ① using microbial fertilizers, microbial pesticides or agricultural antibiotics to replace various fertilizers or chemical pesticides that will cause environmental degradation; (2) Using PHB produced by microorganisms to produce degradable medical plastic products to reduce environmental pollution; ③ Using microorganisms to purify domestic sewage and toxic industrial sewage; ④ Monitoring the pollution degree of the environment by microbial technology, such as Ames method to detect the "three-cause" substances in the environment, and EMB medium to check the intestinal pathogenic bacteria in drinking water.
(5) Microorganisms and human health
Microorganisms are closely related to human health.
First of all, various infectious diseases constitute the main diseases of human beings, and the main means to prevent and treat such diseases are drugs produced by various microorganisms, especially antibiotics.
Since the establishment of genetic engineering, the range and variety of microbial metabolites have been further expanded. In the past, highly effective drugs such as insulin, interferon and interleukin, which could only be produced by animals, were turned to "engineering bacteria" for production.
Steroid hormone drugs closely related to human reproduction and contraception have long been transformed from chemical production to microbial transformation.
In addition, a large number of biological products related to human health and longevity, such as vaccines, vaccines and toxoids, are all products of microorganisms.
No wonder some people estimate that the average life expectancy of human beings has increased by 10 years since the invention of vaccines, and by 10 years since the discovery of antibiotics.
Of course, preventing the excessive population growth is not only the category of microbiology.
Second, the characteristics and development trend of modern microbiology
At present, due to the gradual deepening of molecular biology research, the wide application of various new methods and technologies in microbiology research, the active infiltration and intersection between disciplines, and the raising of a large number of related problems in production practice, it has provided a great impetus for the development of microbiology.
Generally speaking, the characteristics and development trend of modern microbiology have the following six aspects.
(a) The research work is developing at the molecular level.
Due to the rapid development of molecular biology, the whole life science has been promoted to the molecular level.
Microbiology is no exception.
At present, almost all problems in the field of microbiology have been deeply studied at the molecular level, such as cell structure and function, absorption mechanism of nutrients by microorganisms, growth, reproduction and differentiation, metabolic types, pathways and regulation, inheritance, variation and evolution, infection and immunity, classification and identification, etc.
(2) On the basis of in-depth study of basic theories, a number of new disciplines (or potential disciplines) are taking shape.
Such as mycotoxin (science), bacterial plasmid (science), microbial molecular breeding (science), recombinant microbial physiology, protoplast fusion genetics, extreme environmental microbiology, strain preservation (science), miscellaneous bacteria fermentation physiology, methanogenic bacteria biology, anaerobic bacteria biology, archaea (science), virus (science), microbial enzymology, nitrogen-fixing biochemistry, nitrogen-fixing genetics, and microorganism
(3) Microbiology has penetrated, crossed and merged with other disciplines, forming a new frontier discipline.
In the development of disciplines, the mutual penetration, intersection and integration between disciplines often play a growing point and lead role, which not only produces a series of new concepts, theories and technologies, but also produces a series of new frontier disciplines with strong vitality.
This may reflect the effect of "complementarity" and "heterosis" among disciplines.
There are many such examples, such as analytical microbiology, chemical taxonomy, microbial numerical taxonomy and microbial geochemistry.
(d) The wide application of new technologies and methods in microbiology.
Driven by modern mathematics, physics, chemistry and many engineering and technical disciplines, it has created unprecedented advantages for the development of microbiology, mainly in providing new methods, new technologies, new instruments, new equipment and new reagents.
For example, isotope labeling technology, electron microscope technology, X-ray diffraction technology, computer technology, ultracentrifugation technology, electrophoresis technology, chromatography technology, ion exchange technology, mass spectrometry technology, spectrophotometer technology, cell fragmentation technology, immunology technology, amino acid automatic analysis technology, nucleic acid automatic synthesis technology, protein or nucleic acid sequencing technology, low temperature technology, new microbial culture technology, microbial counting technology, microbial rapid identification technology, immobilized biocatalyst technology, etc.
The wide application of these technologies has greatly promoted the research on the structure and function of microbial cells, and gradually raised the original static, descriptive and qualitative research to a new level of dynamic, quantitative, sequencing and positioning.
(e) Expansion to complex ecosystems and macro-scope.
In the biosphere, the living range of microorganisms is the widest and the most stereoscopic.
When people do some research on the common microorganisms around them, their interest gradually turns to a wider and more inaccessible space and various complex ecosystems, which is followed by the birth and development of a number of new disciplines.
Such as extreme environmental microbiology, resource microbiology, tropical mycology, underground ecology, soil microbial ecology, terrestrial microbial ecology, marine microbial ecology, atmospheric microbial ecology and aerospace microbial ecology.
(6) A large number of branches of applied high-tech microbiology are gestating and forming.
Microbiology is a subject deeply rooted in production practice.
Contemporary applied microbiology includes more and more branches, which have the characteristics of strong cross-cutting, high consciousness and wide coverage: ① strong cross-cutting.
Such as fermentation engineering, bacterial metallurgy, water treatment microbiology, fungal genetic engineering, microbial ecological engineering, agricultural microbiology, bio-industry and so on.
② High self-awareness.
At present, driven by the theory and practice of molecular biology, many applied biology disciplines are developing in the direction of strong purpose, high consciousness, strong controllability and high efficiency.
A number of disciplines labeled as "engineering" are among them, such as genetic engineering, cell engineering, biochemical engineering, enzyme engineering, protein engineering and the latest pathway engineering.
③ Wide coverage.
Broadly speaking, the application scope of microorganisms mainly involves industry, agriculture, medicine, environmental protection and national defense. From the perspective of subdivision, each big field can be subdivided into several sub-fields, such as bacterial metallurgy (science), sewage treatment microbiology, biogas fermentation microbiology, applied soil microbiology, microbial biological control (science), agricultural antibiotics, edible fungi, medicinal fungi, medicinal microbiology, human and animal disease microbiology and so on.
Third, the role of microorganisms in the "biological century"
At present, many far-sighted scientists agree that "2 1 century will be the century of biology", the main reasons are as follows: ① It is determined by the development law of material movement.
Generally, the movement of matter develops in the direction of mechanical movement → physical movement → chemical movement → life movement, and the complex movement law must be based on the simple movement law.
At present, human beings have a profound understanding of the objective laws of mechanical movement, physical movement and chemical movement, which provides a good foundation for human beings to further understand the laws of life movement and puts forward an urgent task.
② It is determined by the diversity of the biological world and the long-term understanding of the biological world.
The diversity of the biological world is one of the main characteristics that distinguish it from the non-biological world. Human's understanding of biodiversity is still at a low stage, and biodiversity is the main material basis for human survival.
(3) It is determined by the five major crises faced by contemporary mankind and the urgency of their solution.
④ It is determined by the promotion of life science by other disciplines and the law of "feedback" or "return" of life science.
Microbiology will play a particularly important role in the "biological century".
In natural science, if life science is still a "sunrise science", microbiology can only be regarded as a "dawn science"; If microbiology is a "rich mine", it is still a "rich mine with only a layer of topsoil stripped".
This is because the species, heredity, metabolism and ecological types of microorganisms are highly diverse.
The diversity of microorganisms constitutes the richness of microbial resources, and the richness of microbial resources determines its long-term research, development and utilization.
The development of rich microbial resources by human beings can only be said to be in its infancy.
In any case, the total number of species in microbial communities (including viruses) should greatly exceed the total number of species in animal and plant communities (currently about 1.5 million species), but the former is only110 of the latter.
According to scientific estimates, the number of animal and plant species that really exist in nature is at least several times more than that known today.
The following facts can fully prove how rich microbial resources will be: ① The number of new microbial species is increasing rapidly every year, and only 1500 new species of larger fungi are recorded every year; ② About 90% microorganisms in soil can't be cultivated in the laboratory, and many of them are called "viable bacteria". (3) Because there are corresponding viruses in almost all animals, plants and microorganisms, it is conceivable that in microorganisms, the number of viruses alone may approach or even exceed the sum of the numbers of other animals, plants and microorganisms, not to mention that some hosts can have multiple viruses at the same time (for example, there are more than 300 human viruses found at present! ); ④ The history of human really studying microorganisms is only about 130 years. It is conceivable how many microbial resources can be discovered and utilized in the future!
Among the microorganisms described, the number of species used by humans does not exceed 1%.
For example, out of about 654.38+100000 species of giant mushrooms, about 2000 species are edible, but so far only 80 species have been cultivated in the laboratory, about 20 species have been cultivated commercially, and only 5 or 6 species are common in the market.
As for the special metabolic types of microorganisms, such as the development of microorganisms in extreme environment, it still stays at the starting line!
Fourth, vigorously carry out microbiology research in China.
Due to historical reasons, there is still a big gap between microbiology in China and the international advanced level.
As descendants of the Chinese nation, we have the obligation to make our country's scientific and technological level catch up with the international level, and microbiologists are naturally duty-bound.
To develop microbiology in China, we must proceed from the specific national conditions of our country, concentrate the main manpower and material resources under limited conditions, and capture a few projects with China characteristics, a certain foundation and obvious academic, economic and social benefits as a breakthrough.
Make a breakthrough, popularize one, and then gradually expand the results.
Therefore, the research focus at this stage should be on the research of applied theory.
(A) resource investigation and classification identification
China has a vast territory, complex terrain, three zones of cold and warm, and diverse ecological environment, and is one of the few countries with a large number of microbial resources.
However, at present, the resource investigation and classification team is weak, the technology is backward and the published results are few.
According to statistics, the number of bacteria and fungi currently studied in China only accounts for 5 ~ 10% of the known number in the world.
In this field, efforts should be made to investigate the strain resources with China characteristics and application prospects in the near future, so as to promote the development of morphology, classification and identification (especially new identification methods).
For example, the investigation of nitrogen-fixing microbial resources, the classification and identification of rhizobia; Screening and chemical classification of new antagonistic actinomycetes: mycorrhizal resources investigation: edible and medicinal fungi resources investigation and fungal classification system research: entomogenous microorganisms and insect baculovirus resources investigation: isolation, detection and disease control of main crop virus pathogens; Development of single cell protein resources; Investigation on the resources of extreme microorganisms (especially halophilic, alkalophilic and thermophilic bacteria) and study on the classification and identification of strains; Wait a minute.
(2) Physiological metabolism and fermentation engineering
The achievements of physiological metabolism research can promote the development of many application fields such as fermentation engineering, agriculture and medical microbiology.
There are many research projects to be carried out in this field, such as recombinant microbial physiology, immobilized microbial physiology, mixed culture microbial physiology, extreme microbial physiology, photosynthetic bacteria physiology, anaerobic bacteria physiology, etc. Biochemistry of nitrogen fixation, synthetic pathway of secondary metabolites (such as antibiotics) and metabolic regulation; Multi-stage continuous culture kinetics; Secretion mechanism of extracellular enzymes, enzyme inhibitors and activators; Growth law of high-density bacteria; Study on non-grain fermentation raw materials: Study on improving product concentration, conversion rate and productivity (g/L h) in fermentation production: Study on oxygen carrier in liquid fermentation: microbial decomposition mechanism of cellulose, lignin and hemicellulose, microbial hydrogen production mechanism; Research on biosensor, on-line control of fermentation by computer; Inhibitory effect of effective components of Chinese herbal medicine on virus: mildew mechanism of industrial products; Research and Utilization of Metabolites from Anaerobic Bacteria: Wait a minute.
(3) Genetic variation and strain selection
The research and improvement of microbial germplasm resources is an indispensable work in microbiology for a long time.
Since the emergence of genetic engineering, microbial genetic breeding has reached a new level.
In the field of genetic variation and strain selection, the problems worthy of further study are:
Principle and technology of microbial molecular breeding, principle and technology of protoplast moving species; Genetic stability of recombinant bacteria; Actinomyces genetics; Establish various new receptor-vector systems related to fermentation engineering (such as Bacillus, Corynebacterium, yeast, actinomycetes, filamentous fungi and some extreme microorganisms); Genetics of rhizobia, introducing nitrogen-fixing genes into non-leguminous plants; Construction of cellulose, lignin and hemicellulose decomposing engineering bacteria: genetic principle of pathogen drug resistance; And the breakthrough of traditional strain screening technology.
(D) Ecological theory and environmental protection practice
In the research field of microbial ecology, in-depth work is rare, and there is a lot of work waiting for people to study.
For example, the investigation of new microbial groups in soil, the population structure and function of soil microorganisms; * * * Molecular basis of mutual recognition between organisms and pathogenic microorganisms and their hosts; Theoretical basis of using microorganisms to control pests and diseases; Microbial ecological problems in traditional brewing in China: a microecological study: Species, mildewing mechanism and control methods of moldy microorganisms; The living state of important pathogenic bacteria in nature; Microbial flora in rumen and cecum (horses, etc.) ) and cockroach intestine and its cellulose decomposition mechanism; Anaerobic degradation ecology, refractory organic degradation bacteria and comprehensive utilization of "three wastes"; Marine microbial ecology; And toxic fungi and mycotoxins; Wait a minute.
(D) Ecological theory and environmental protection practice
In the research field of microbial ecology, in-depth work is rare, and there is a lot of work waiting for people to study.
For example, the investigation of new microbial groups in soil, the population structure and function of soil microorganisms; * * * Molecular basis of mutual recognition between organisms and pathogenic microorganisms and their hosts; Theoretical basis of using microorganisms to control pests and diseases; Microbial ecological problems in traditional brewing in China: a microecological study: Species, mildewing mechanism and control methods of moldy microorganisms; The living state of important pathogenic bacteria in nature; Microbial flora in rumen and cecum (horses, etc.) ) and cockroach intestine and its cellulose decomposition mechanism; Anaerobic degradation ecology, refractory organic degradation bacteria and comprehensive utilization of "three wastes"; Marine microbial ecology; And toxic fungi and mycotoxins; Wait a minute.
(5) Mechanism and practice of infection and immunity.
The research contents in this aspect mainly include: the molecular mechanism of pathogenic bacteria; Isolation, identification and pathogenicity of pathogenic anaerobic bacteria; Anti-biological warfare; Isolation and identification of new pathogenic bacteria; New vaccines, new biological products, genetic engineering and vaccine production, multivalent genetically engineered vaccines; Study on Monoclonal Antibodies: Wait a minute.
(6) Others
Study on microbiological methods; Modern strain preservation technology; Establish a microbial database; Standardization of laboratory reagents; Commercial simple and rapid strain identification box; Wait a minute.
To sum up, we can know that microorganisms are a huge team in the biological world.
Whether their functions are beneficial or harmful to people mainly depends on people's understanding and mastery of their activities.
Numerous facts vividly prove that since human beings have known microorganisms and gradually mastered their activity rules, it is possible to make previously unprofitable microorganisms profitable, small ones profitable, harmful ones tiny, harmless and even beneficial, thus greatly promoting human progress.
This is the fundamental purpose of our research on microbiology.