Enzyme Production through Solid State Fermentation (SSF)
Enzyme Production through Solid State Fermentation
 
The Origins
Jokichi Takamine was the first to describe the industrial process of enzyme production through solid state fermentation – also called Koji process. He drew his inspiration from traditional methods. Our ancestors did not wait for the mechanisms of fermentation to be understood, or the existence of microorganisms to be known, in order to produce fermented food.
 
Fermented Products
More than 3,500 traditional fermented foods, whether from vegetable or animal origins, can be found worldwide (dairy products such as yogurt or cheese; meat products such as sausage; bread and pastries; fermented vegetables such as sauerkraut or olives).

In Africa, food is made from fermented starch (yam or manioc).

In Europe, cheese, bread and yogurt are most popular.

In Asia, it’s from soy bean or fish that everyday foodstuffs such as soy sauce, or miso soup, are produced...
 
Solid State Fermentation vs Liquid Fermentation
The solid state fermentation is the traditional process to produce enzymes, as developed by Jokichi TAKAMINE. Over the years, the technology has evolved to improve the fermentation productivity. Nevertheless, the fundamental qualities and advantages of the SSF were kept.
Actually, the SSF allows to produce a wider range of enzymatic activities than Deep Tank Liquid Fermentation ( DTF).
An other advantage of SSF, as implemented by Shin Nihon in Japan, is the capability to produce very specific enzymes in small batches.
 
A process for the future
The phrase « Solid State Fermentation » - or SSF - gave more than 57,000 results, from 2004 to 2009, with the scientific publication search engine Scirus. In other words twice more than was the case during the 5 previous years. Just in terms of scientific periodicals, the number of publications has risen, from 2088 to 4354.

Interest for enzymes and their manufacturing process is related to their capacity to transform biomass. Current trends in SSF have emphasized applications of SSF for organic environmental remediation and detoxification of residues from industrial farming, organic transformation of crops and crop residues, the nutritional enrichment and production of value-added products such as biologically active metabolites (antibiotics, alcaloids, enzymes, organic acids, organic pesticides, mycopesticides and weedkillers), organic surfactant agents, biofuels, fragrance components, etc.
 
The main steps of the process
The two main steps of enzyme production are fermentation and purification. The enzymes produced by Shin Nihon Chemical are produced from non-genetically modified sources. The traditional Koji Process is introduced here.
 
Fermentation phase
Culture
Microorganisms such as Aspergillus oryzae are cultivated on a substrate of wheat bran for instance. The inoculated substrate is then laid out on plates that are 4 to 5 cm high. They are then placed in an incubation room, where air and temperature conditions are controlled.

A large-sized mycellium grows on the substrate.
 
The Substrate
Non-soluble, the substrate acts as a physical foundation and a nutriment for the yeast or mushrooms. An ideal substrate has to contain all of the nutriments needed to enable growth to occur. The size of the particles in the substrate is also an important parameter. If they’re too small, they can form lumps, hindering the growth process. If they are too large, exposure to the air, respiration is improved but the areas which the microorganisms can bite into are reduced. The aw (Water activity) is another parameter which needs to be mastered.
 
The purification phase
Depending on their final use, enzymes come in a liquid state, granules or powder . After fermentation, the enzymes are extracted with water from the substrate. The product is then formulated, standardized as a liquid, powder or
granule, depending on the request. powder , liquid or granules .
 
To find out more

(1) Fermented foods (Inra)

(2) Solid-state fermentation. Pandey, Ashok (2008, June 13). SciTopics. Retrieved February 16, 2010, from SCITOPICS

Genomics of Aspergillus oryzae: Learning from the History of Koji Mold and Exploration of Its Future. Masayuki Machida, Osamu Yamada, and Katsuya Gomi, DNA Res. 2008 August; 15(4): 173–183. NCBI