Cell wall for higher growth rates in diatoms. In brown algae, phlorotannins may be a constituent of the cell walls. The group Oomycetes, also known as water molds, are saprotrophic plant pathogens like fungi. Until recently they were widely believed to be fungi, but structural and molecular evidence has led to their reclassification as heterokonts, related to autotrophic brown algae and diatoms. Unlike fungi, oomycetes typically possess cell walls of cellulose and glucans rather than chitin, although some genera (such as "Achlya" and "Saprolegnia") do have chitin in their walls. The fraction of cellulose in the walls is no more than 4
Natural building construction, as hempcrete's density is 15% that of traditional concrete. Rammed earth is a wall system made of compacted earth, or another material that is compacted. It is extremely strong and durable. Quality rammed earth walls are dense, solid, and stone-like with great environmental benefits and superior low maintenance characteristics. As an option depending on climate rigid insulation can be placed inside the wall. Similarly, depending on seismic concerns bamboo or other tensile natural materials can be used to reinforce the wall. Rammed earth has been used for around 10,000 years in all types of buildings from low rise to