Biomedical Engineering Reference
In-Depth Information
demand of feed protein, since the 1960s many countries and regions have been
committed to research and application of SCP and have made gratifying progress.
In recent years, with the increasing demand of SCP, there has been a shortage of
raw material for SCP. Since the 1990s, the production and research of SCP revealed
some new trends: The key point of the SCP production and research focus is on
the search for cheap raw materials to reduce economic costs. The raw materials
for SCP fermentation and production are abundant and mainly in the following
four categories: The first category is industrial and agricultural waste, including
wastewater from pulping and paper, glutamate production, tofu making, the sugar
industry, beer production, and organic chemistry industry. The second category
is industrial residue, including residue of orange, potato, cassava, grape, and
sugarbeet; and the residuals of sugar making and vinegar and cornstarch production.
The third category is petroleum resources. Fourth is cellulose raw material, which
is available in a great amount, including agricultural and forestry wastes [
1
,
2
].
China is a big agricultural country and ranks first around the world for average
annual output of crop straw. The average annual output of crop straw, which is
the most easily obtained biomass resource, is about 700 million tons in China.
However, as the main component of biomass, cellulose is difficult to degrade; its
development and use are limited for a long time, and most of its fate is burning
or returning to the field. To obtain fully reasonable and effective use of the natural
cellulose resources, many countries have been dedicated to the study of the various
processing methods for resources. Among them, production of SCP has become a
potential orientation [
3
]. To produce SCP from cellulosic raw materials not only
can save many foods, relieve protein shortage, reduce feed costs, and promote
revolution of the feed industry, but also promote the development of aquaculture
to increase the output of livestock and poultry products, improve people's diet
structure, and finally enhance people's living standards. Meanwhile, the use of
cellulosic biomass can curb the burning of straw and other agricultural waste, reduce
environmental pollution, protect the ecological environment to form a virtuous
cycle, and ultimately achieve the sustainable development of agriculture and society.
Therefore, the use of agricultural waste and other renewable resources to produce
protein feed is imperative.
The history of human production of food by microorganisms has existed for
thousands of years, and the modern culture of microorganisms as food was
begun in Germany. As early as 1890, the Germans first found the possibility of
microorganisms as a direct human and animal nutrition protein resources, and in
1915, the industrial production of edible yeast using molasses as the raw material
was realized. After World War I, many countries began to study the production of
feed yeast. After World War II, to ease the food deficit, edible yeast production
played an important role in relieving postwar food shortages in Germany and the
former Soviet Union, and SCP entered rapid development. In 1967, an international
conference on SCP was held at the Massachusetts Institute of Technology, and SCP
was verified there as one of the important ways to solve food and feed problems [
4
].
The research institute from the U.S. Department of Agriculture selected a microbial
strain that could not only fix the nitrogen in the air but also use the crop straw fibers
