Process for the production of useful cultures and/or metabolites

A continous process for the production of useful metabolites from a carbohydrate-containing nutrient medium by fermentation of said medium, said process comprising the steps of:

• (a) continously introducing a microorganism culture comprising a inoculum and said nutrient medium to the upper end of a tower-like fermentor sealed off from the ambient atmosphere and divided into a vertical series of generally cylindrical fermentation zones arranged generally vertically along the vertical axis of said tower-like fermentor, each said fermentation zone being divided into substantially liquid-tight, continously rotating segments, whereby said culture is initially introduced into a continuously rotating segment of the first and uppermost of said fermentation zones;
• (b) continously rotating said continuously rotating segment at least about three-fourths of a revolution to a gravity flow transfer means for transferring the culture to the second and next-to-uppermost of said fermentation zones, the retention time in a higher fermentation zone ranging from about 1 to about 100 minutes;
• (c) continuously transferring said culture by gravity flow to a continuously rotating segment of the said second and next-to-uppermost of said fermentation zones, the retention time in said next-to-uppermost of said fermentation zones being generally equal to the retention time in said uppermost fermentation zone;
• (d) continuing the transfer of said culture by gravity flow to continuously rotating segments of successively lower fermentation zones at least until such culture is in a logarithmic growth phase;
• (e) continuously withdrawing a portion of the culture in the logarithmic growth phase from a said lower fermentation zone before the concentration of metabolites in the culture reaches a level high enough to stop growth of the culture, and pumping the thus-withdrawn portion at a gauge pressure below about one atmosphere to said first and uppermost fermentation zone without exposing said thus-withdrawn portion to the ambient atmosphere or to contamination with extraneous microorganisms;
• (f) withdrawing metabolites from at least the lowest of said fermentation zones without exposure of said zone to the ambient atmosphere or to contamination with extraneous microorganisms;
• and
• (g) recovering useful metabolities from the thus-withdrawn metabolites.

A process for stimulating the growth of a microorganism culture in a series of growth zones and withdrawing metabolites produced by said culture from a said growth zone, said process comprising the steps of:

• (a) introducing a microorganism culture comprising an inoculum and a liquid nutrient medium to the upper end of a tower-like production unit divided into a generally vertical series of tray-like growth zones, whereby said culture is introduced to the uppermost of said tray-like growth zones, each said growth zone having a drain opening and being subdivided into substantially liquid-tight, continuously moving, movable segments for continously agitating the thus-introduced culture in said zone and for advancing said culture toward said drain opening;
• (b) advancing in a said movable segment, said culture toward said drain opening in said uppermost of said tray-like growth zones;
• (c) obtaining gravity flow of said culture through said drain opening into a movable segment of the next lowest or next-to-uppermost of said tray-like growth zones;
• (d) repeating said steps (b) and (c) in said next-to-uppermost of said tray-like growth zones, thereby obtaining gravity flow to a movable segment of the next lowest tray-like growth zone below said next-to-uppermost of said tray-like growth zones;
• (e) further repeating said steps (b) and (c) in successively lower tray-like growth zones until substantial multiplication of the microorganisms in said culture has been obtained;
• (f) withdrawing a portion of said culture from a said tray-like growth zone;
• (g) withdrawing said metabolites from at least one of said tray-like growth zones;
• and
• (h) introducing partly metabolized nutrient material and microorganism cultures in a logarithmic growth phase into a higher tray-like growth zone, thereby increasing the ratio of live, mature, rapidly growing, metabolite-tolerant microorganisms to nutrient material in said higher tray-like growth zone and shortening any lag time in said growth zone.