Five days after the space station accident.

There are still six days left until Tianzhou 37.

The old cat finished the routine work of carrying the battery board, and when he entered the door, he found Tang Yue lying on the table and sleeping unconscious, drooling on the keyboard.

"Wake up, wake up." The old cat put the things in his hand on the table, and then poked him, "Halazi is going to run to the ground." ”

Tang Yue opened his eyes, raised his head, and looked left and right in a daze, half of his face was printed with red AWSD.

"So sleepy?" The old cat held the dropper in his hand and stood in front of the shelf to take care of the tomatoes, and he turned the planting box in one direction so that the plants would be evenly lit, "Little eight, little ten, little eleven...... The growth is very good, and grandpa is very happy. ”

"It was too late to fight the landlord last night." Tang Yue yawned and rubbed his sore neck, "What about Mai Dong?" ”

Last night, Tang Yue's old cat and Mai Dong played cards until half past one in the morning, since graduating from college, Tang Yue did not stay up all night, a night of fierce fighting, he lost dozens of games in a row, Mai Dong also lost dozens of games, and finally the two lost bankrupt, and the old cat made a lot of money.

"I'm here." The girl replied, and she yawned too, "I'm so sleepy too...... Sleepy, cold and hungry. ”

There are only two compressed biscuits left, Mai Dong consumes dry food at a small rate a day, trying to maintain her strength, her daily life now is to eat, sleep, sleep, eat, sleep

"What is this?" Tang Yue noticed that the thing the old cat got back was a plastic box, and there was a plexiglass petri dish the size of a palm in the box.

Tang Yue took the petri dish out of the box, held it in his hand and looked at it curiously, there was a layer of transparent gelatinous matrix at the bottom of the petri dish, like a colorless jelly, the jelly was covered with colorful irregular spots, the largest was the size of an adult's thumb, monopolizing, in a regular oval, and the small ones were like scattered rice grains, and some had fine hairs.

"Moldy jelly?"

"The colonies I'm culturing." The old cat turned his head and looked, "I have to leave a little seed of life in this world, don't I?" ”

"What do you mean?" Tang Yue asked, "Are these bacteria the seeds of life?" Do you want to sow them and let them evolve into higher lifeforms? ”

"What's impossible?" The old cat carefully watered the tomatoes, "Don't forget that you were once such simple beings, as long as you give them enough time, one day, they will also work miracles." ”

"But it took us three billion years."

"The universe will give them three billion years."

"Where do these bacteria come from?" Tang Yue asked.

The old cat turned around and pointed at Tang Yue with his chin, meaning "Where is there a second source of pollution in the whole of Mars besides you?" ”

"I use compressed biscuits and compost extract as nutrients, agar as the culture medium, and the bacteria basically come from you, and the colonies here include Staphylococcus epidermidis, Staphylococcus aureus, Streptococcus, Willon coccus and E. coli." The old cat walked over, took the petri dish, and looked at the light outside the window, "They are distributed in your skin, respiratory tract and intestines. ”

"Gut?" Tang Yue was startled and subconsciously covered his buttocks.

"What did you do to me while I was sleeping?"

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"I've been on Mars for a long time, and even bacteria find it cute." Tang Yue propped his head, and slowly rotated the petri dish with his other hand, "How many different bacteria are in here?" ”

"There are as many different bacteria as there are different colonies." The old cat replied, "Those small round colonies that are yellowish or white are staphylococcus, and those opaque gray-green round colonies are Viron cocci...... I put them outdoors to test their tolerance to the Martian environment, and it turned out that the vast majority of bacteria hung up, and only a few anaerobes persisted. ”

Growing colonies in the earth environment is a rather complicated job, which requires strict disinfection to prevent pollution, but it is much simpler to do this on Mars, as long as the old cat leaves Kunlun Station and is far away from Tang Yue's living area, then it can avoid almost all interference.

Tang Yue stared at the colonies in the petri dish, the growth of these microorganisms is actually not optimistic, most of the colonies are on the verge of extinction, it may be that the culture medium made by the old cat is not nutritious, or it may be that the Martian environment is too harsh, but they are still trying their best to expand, trying to occupy every square centimeter of the culture medium.

"If they can really spread, then the resulting biosphere is very different from what is certainly on Earth." Tang Yue said, "Only anaerobic bacteria can survive here, so all living things may not need oxygen in the future, and it will be a new life form." ”

The external form of life is fundamentally determined by the most basic energy utilization, the vast majority of life on the earth depends on respiration to provide energy, respiration is an oxidation reaction, the decomposition of glucose into pyruvate and then converted into adenosine triphosphate, this energy transmission chain exists in almost all living organisms, so there is a respiratory system, there is a circulatory system.

"Then you are the creator god." The old cat said, "This is a grand myth like Pangu opening the world and Nuwa creating man...... But who would have thought that the so-called myth was just a man scraping a little saliva from his mouth on an ordinary afternoon and applying it to a petri dish. ”

"No matter how major the historical turning point is, it is just an ordinary day." Tang Yue said, "After all, there is no BGM in life. ”

He looked up and felt the great wheel of history rumbling over his head.

"It sounds legendary, but it's actually impossible." The old cat said, "Do you really think that the colonies in this petri dish will be the source of the next civilization?" Even if these bacteria are not dependent on oxygen, they are still the product of evolution in the Earth's environment, and the heterotrophic flora in the human body cannot survive without enough organic matter on Mars...... To survive in this ghostly place, you need auto-oxygen bacteria, such as sulfide bacteria or certain archaea. ”

Tang Yue frowned.

"Then you just said that this is the seed of life?"

"Nonsense." "I didn't think about cultivating the next civilization with bacteria, I don't have that long lifespan, this is just a small experiment I did before, testing the effects of radiation from the Martian environment on the human microbiota." ”

It walked over, picked up the petri dish on the table, squinted one eye, and pointed out the colonies on the substrate to Tang Yue one by one, "Huh...... You see, these staphylococci are dying, the colonies are declining, yesterday they were twice as large as this, half of them died in 24 hours, the streptococcus is about to hang, this color is unhealthy, and there are Malassezia, the colonies are no longer visible, it is obviously dead. ”

"And what about this?" Tang Yue stretched out his finger and pointed to a black colony in the middle of the petri dish, it was not the largest of all the colonies, but it showed no signs of decline, it was quite vigorous, "This one grows very well." ”

The old cat stared at the oval patch for a long time, rubbing its chin.

"Is this Candida? Or is it a monosa? Wrong...... Not right......"

The old cat shook his head slowly.

"Huh?" Tang Yue asked, "What's wrong?" ”

"Mutation, it should be mutation." The old cat finally judged, "This is a mutant strain." ”