Answer

If you mean a one-sensed microscopic jiva like a bacterium/nigoda, then in Jain Dharma it cannot consciously attain samyak darshan or intentionally do punya in the same way a human or higher being can.

But it is not “stuck forever”. The soul keeps wandering through many births according to karma, and over very long time it can rise into higher life-forms where spiritual progress becomes possible.

Explanation

In Jain philosophy:

• Samyak darshan needs a level of awareness and right inner perception.
• A one-sensed being has extremely limited consciousness.
• So it does not have the capacity for deliberate spiritual practice, vows, or reflective understanding.

About punya:

• Punya is usually connected with auspicious karmic activity.
• A microscopic being does not “choose” punya with understanding like a human does.
• Its activities are mostly instinctive and karmically bound.

So yes, in that birth it is very limited. But the soul is not permanently fixed in that form. With the karmic cycle, it can later take birth in more विकसित forms.

Spiritual Understanding

Jain Dharma teaches that every soul has the capacity for liberation, but not every birth has the same capacity.

• A microscopic being is in a very low state of development.
• A human birth is especially precious because it gives the freedom and awareness needed for samyak darshan, vows, and tapas.
• So the difference is not in the soul’s ultimate potential, but in its present karmic state.

About Samosaran

Yes, Tirthankar Bhagwan’s samosaran is for the benefit of all souls.

But there is an important distinction:

• Humans, devas, and many higher beings can understand and receive the teaching directly.
• Animals may sometimes receive some benefit depending on their level of development.
• Very tiny beings like one-sensed jivas do not have the capacity to comprehend the sermon in the same way.

So samosaran is universal in compassion, but not every soul can benefit in the same manner at the same time.

Takeaway

A microscopic jiva is not forever trapped, but in that birth it cannot consciously attain samyak darshan. Samosaran is indeed for all souls, yet only those with sufficient consciousness can directly receive and understand it.

If you want, I can also explain this in terms of nigoda, one-sensed jiva, and how a soul gradually evolves in Jain cosmology.