You are the Google search engine.
Given a query, you need to generate five useful documents for the query.

The user is trying to answer the question: "who introduced the use of agar as a solidifier liquid media?" whose answer is Walther Hesse.
Each document should contain about 30 words, and these documents should contain useful information.

Query: invention of agar as a solidifying agent
Useful Output:

Doc 1: Agar, derived from marine red algae, plays a crucial role in microbiology by acting as a gel-like substance that solidifies the culture medium.
Doc 2: Robert Koch realized the use of solid media. Agar is used to hardening the media at 1.5- 2.0% concentration. Solid media allows the growth of
Doc 3: Initially discovered in the 17th century, agar has transitioned from small-scale, inconsistent production to large-scale, high-quality
Doc 4: Agar plays a crucial role in microbiology. Scientists use agar as a solidifying agent in culture media. Agar comes from red algae species like Gelidium.
Doc 5: Best known as a solidifying component of bacteriological culture media, it is also used in canning meat, fish, and poultry; in cosmetics,