Industrial microbiology — Which species of Acetobacter (now Komagataeibacter) is well known for producing extracellular cellulosic strands (bacterial cellulose) that hold cells in a lime-like layer or pellicle?

Introduction / Context:
Bacterial cellulose is a high-purity, nanofibrillar material produced by certain acetic acid bacteria. Recognizing the classic producing organism is important for questions on biomaterials, fermentation technology, and biofilms at air–liquid interfaces.

Given Data / Assumptions:

• Several Acetobacter (now Komagataeibacter) species are involved in vinegar fermentation and biofilm formation.
• Bacterial cellulose forms visible pellicles/strands that can hold cells in a cohesive layer at the surface.
• The item asks for the best-known cellulose producer.

Concept / Approach:
Acetobacter xylinum (more precisely Komagataeibacter xylinus) is the textbook bacterium for cellulose pellicle formation in static cultures, yielding “nata de coco” and other biomaterial applications. Other listed species are not the archetypal cellulose producers in teaching literature.

Step-by-Step Solution:

Verification / Alternative check:
Industrial and academic sources repeatedly cite K. xylinus as a major source of bacterial cellulose with unique physicochemical properties.

Why Other Options Are Wrong:

• A. curvum, A. schuetzenbachii: acetic acid bacteria without the classic cellulose hallmark.
• “Accetobacter orleanense”: spelling inconsistent and not the standard cellulose model organism.

Common Pitfalls:
Confusing vinegar producers broadly with the specific cellulose-producing strains; only certain lineages form robust pellicles.

Final Answer:
Acetobacter xylinum