• Thermoduric Bacteria in Milk Pasteurization:
• Microbacterium lacticum:
• Small, non-spore-forming, Gram-positive coryneform rod that exhibits extreme heat resistance.
• Possesses nearly $100\%$ survival rate through standard HTST ($72^\circ\text{C}$ for $15\text{ s}$) and LTLT ($63^\circ\text{C}$ for $30\text{ min}$) milk pasteurization, frequently surviving exposures up to $80 - 85^\circ\text{C}$ for 10 minutes.
• Serves as a major indicator of uncleaned milking equipment biofilms.
• Conclusion: Microbacterium (Option 1).

Correct option: (1) Microbacterium