Hercules Inc. has signed letters of intent to acquire Minnesota-based Pure Culture Products Inc. and undertake a joint venture with IGI Biotechnology Inc. of Columbia, Md., the Wilmington, Del., company announced last week.

The joint venture with IGI is aimed at forming a new company, WeyChem Inc., which will manufacture and market whey-based fermentation products worldwide.

The products will include lactic acid salts and Weyco-Serv mold inhibitor and food preservative. In addition, the new company will manufacture and market sugar-based poly-levulan polysaccharide gum for food and other applications.

Pure Culture Products, which manufactures yeast and autolyzed yeast, is a division of Amoco Chemicals Corp., which is a subsidiary of the Standard Oil Co.

Pure Culture Products operates a plant in Hutchinson, Minn., about 60 miles west of Minneapolis. The plant employs about 47 people.

Exact terms of the proposed acquisition and the joint venture were not disclosed, but the transactions are expected to be completed by the end of this year.

"The acquisition of Pure Culture Products and the formation of WeyChem Inc. are significant steps for PFW, the food ingredients and fragrances business group of Hercules Specialty Chemicals Co.," a Hercules spokesman said.

"The proposed transactions will broaden PFW's food ingredient product lines by creating a position in the biochemical production of natural food ingredients through fermentation and enzyme processing," the spokesman said.