ROMA ARCHEOLOGICA & RESTAURO ARCHITETTURA 2021. “Send in the Bugs. The Michelangelos Need Cleaning” [= Laboratori Enea i batteri ‘restauratori’ per riparare dipinti, affreschi e statue], NYT (31 May, 2021): C1. S.v., “Roma, Casina Farnese sul Palatino,” in: ADNKRONOS / ARTE (10/04/2015).

1). ITALIA – Send in the Bugs. The Michelangelos Need Cleaning. NYT (31 May, 2021): C1.

Last fall, with the Medici Chapel in Florence operating on reduced hours because of Covid-19, scientists and restorers completed a secret experiment: They unleashed grime-eating bacteria on the artist’s masterpiece marbles.

ROMA ARCHEOLOGICA & RESTAURO ARCHITETTURA 2021. "Send in the Bugs. The Michelangelos Need Cleaning" [= Laboratori Enea i batteri 'restauratori' per riparare dipinti, affreschi e statue], NYT (31 May, 2021): C1. S.v., ADNKRONOS / ARTE (10/04/2015).

FLORENCE — As early as 1595, descriptions of stains and discoloration began to appear in accounts of a sarcophagus in the graceful chapel Michelangelo created as the final resting place of the Medicis. In the ensuing centuries, plasters used to incessantly copy the masterpieces he sculpted atop the tombs left discoloring residues. His ornate white walls dimmed.

Nearly a decade of restorations removed most of the blemishes, but the grime on the tomb and other stubborn stains required special, and clandestine, attention. In the months leading up to Italy’s Covid-19 epidemic and then in some of the darkest days of its second wave as the virus raged outside, restorers and scientists quietly unleashed microbes with good taste and an enormous appetite on the marbles, intentionally turning the chapel into a bacterial smorgasbord.

ROMA ARCHEOLOGICA & RESTAURO ARCHITETTURA 2021. "Send in the Bugs. The Michelangelos Need Cleaning" [= Laboratori Enea i batteri 'restauratori' per riparare dipinti, affreschi e statue], NYT (31 May, 2021): C1. S.v., ADNKRONOS / ARTE (10/04/2015).

“It was top secret,” said Daniela Manna, one of the art restorers.

On a recent morning, she reclined — like Michelangelo’s allegorical sculptures of Dusk and Dawn above her — and reached into the shadowy nook between the chapel wall and the sarcophagus to point at a dirty black square, a remnant showing just how filthy the marble had become.

She attributed the mess to one Medici in particular, Alessandro Medici, a ruler of Florence, whose assassinated corpse had apparently been buried in the tomb without being properly eviscerated. Over the centuries, he seeped into Michelangelo’s marble, the chapel’s experts said, creating deep stains, button-shaped deformations, and, more recently, providing a feast for the chapel’s preferred cleaning product, a bacteria called Serratia ficaria SH7.

ROMA ARCHEOLOGICA & RESTAURO ARCHITETTURA 2021. "Send in the Bugs. The Michelangelos Need Cleaning" [= Laboratori Enea i batteri 'restauratori' per riparare dipinti, affreschi e statue], NYT (31 May, 2021): C1. S.v., ADNKRONOS / ARTE (10/04/2015).

“SH7 ate Alessandro,” Monica Bietti, former director of the Medici Chapels Museum, said as she stood in front of the now gleaming tomb, surrounded by Michelangelos, dead Medicis, tourists and an all-woman team of scientists, restorers and historians. Her team used bacteria that fed on glue, oil and apparently Alessandro’s phosphates as a bioweapon against centuries of stains.

In November 2019, the museum brought in Italy’s National Research Council, which used infrared spectroscopy that revealed calcite, silicate and other, more organic, remnants on the sculptures and two tombs that face one another across the New Sacristy.

ROMA ARCHEOLOGICA & RESTAURO ARCHITETTURA 2021. "Send in the Bugs. The Michelangelos Need Cleaning" [= Laboratori Enea i batteri 'restauratori' per riparare dipinti, affreschi e statue], NYT (31 May, 2021): C1. S.v., ADNKRONOS / ARTE (10/04/2015).

That provided a key blueprint for Anna Rosa Sprocati, a biologist at the Italian National Agency for New Technologies, to choose the most appropriate bacteria from a collection of nearly 1,000 strains, usually used to break down petroleum in oil spills or to reduce the toxicity of heavy metals. Some of the bugs in her lab ate phosphates and proteins, but also the Carrara marble preferred by Michelangelo.

“We didn’t pick those,” said Bietti.

Then the restoration team tested the most promising eight strains behind the altar, on a small rectangle palette spotted with rows of squares like a tiny marble bingo board. All of the ones selected, she said, were nonhazardous and without spores.

“It’s better for our health,” said Manna, after crawling out from under the sarcophagus. “For the environment, and the works of art.”

Sprocati said they first introduced the bacteria to Michelangelo’s tomb for Giuliano di Lorenzo, Duke of Nemours. That sarcophagus is graced with allegorical sculptures for Day, a hulking, twisted male figure, and Night, a female body Michelangelo made so smooth and polished as to seem as if she shone in moonlight. The team washed her hair with Pseudomonas stutzeri CONC11, a bacteria isolated from the waste of a tannery near Naples, and cleaned residue of casting molds, glue and oil off her ears with Rhodococcus sp. ZCONT, another strain which came from soil contaminated with diesel in Caserta.

It was a success. But Paola D’Agostino, who runs the Bargello Museums, which oversees the chapels and which will officially reveal the results of the project in June, preferred to play it safe on Night’s face. So did Bietti and Pietro Zander, a Vatican expert who joined them. They allowed the restorers to give her a facial of micro-gel packs of xanthan gum, a stabilizer often found in toothpaste and cosmetics that is derived from the Xanthomonas campestris bacteria. The head of the Duke Giuliano, hovering above his tomb, received similar treatment.

Sprocati took her bugs elsewhere. In August, her group of biologists used bacteria isolated from a Naples industrial site to clean the wax left by centuries of votive candles from Alessandro Algardi’s baroque masterpiece, a colossal marble relief in St. Peter’s Basilica in Rome of the Meeting of Attila and Pope Leo.

The bacteria strains got back to the Medici Chapel, which had reopened with reduced hours, in mid-October. Wearing white lab coats, blue gloves and anti-Covid surgical masks, Sprocati and the restorers spread gels with the SH7 bacteria — from soil contaminated by heavy metals at a mineral site in Sardinia — on the sullied sarcophagus of Lorenzo di Piero, Duke of Urbino, buried with his assassinated son Alessandro.

“It ate the whole night,” said Marina Vincenti, another of the restorers.

The Medicis were more accustomed to sitting atop Florence’s food chain.

In 1513, Giovanni di Lorenzo de Medici became Leo X — the first Medici pope. He had big plans for a new sacristy for the interment of his family, including his father, Lorenzo the Magnificent, the powerful ruler of Florence who largely bankrolled the Renaissance. Il Magnifico is now buried here too, under a modest altar adorned with Michelangelo’s Madonna and Child, flanked by saints that also had their toes nibbled by cleansing bacteria. But back then his coffin waited, probably on the Old Sacristy floor. He was soon joined by Leo X’s brother, Giuliano, and his nephew, Lorenzo, the Prince to whom Machiavelli dedicated his treatise on wielding power.

“You had coffins waiting to be buried,” said D’Agostino. “It’s kind of gloomy.”
Image

Pope Leo X hired Michelangelo to design and build the mausoleum. The pope then promptly died of pneumonia. In the ensuing years, Michelangelo carved the masterpieces and then ran afoul of his patrons.

In 1527, with the Sack of Rome, Florentines, including Michelangelo, supported a Republic and overthrew the Medicis. Among the ousted princes was Lorenzo di Piero’s sometimes volatile son, Alessandro, whom many historians consider a real piece of work. Michelangelo couldn’t stand him, and when the Medicis stormed back, it was Michelangelo’s turn to flee.

In 1531, the Medici Pope Clement VII pardoned Michelangelo, who went back to work on the family chapel. But by that time, Alessandro had become Duke of Florence. Michelangelo soon left town, and the unfinished chapel, for good.

“Alessandro was terrible,” said D’Agostino.

Alessandro’s relative, known as the “bad Lorenzo,” agreed and stabbed him to death in 1537. The duke’s body was rolled up in a carpet and plopped in the sarcophagus. It’s unclear if his father, Lorenzo, was already in there or moved in later.

ROMA ARCHEOLOGICA & RESTAURO ARCHITETTURA 2021. "Send in the Bugs. The Michelangelos Need Cleaning" [= Laboratori Enea i batteri 'restauratori' per riparare dipinti, affreschi e statue], NYT (31 May, 2021): C1. S.v., ADNKRONOS / ARTE (10/04/2015).

“A roommate,” D’Agostino said.

In 2013, Bietti, then the museum’s director, realized how badly things had deteriorated since a 1988 restoration. The museum cleaned the walls, marred by centuries of humidity and handprints, revealed damages from the casts and iron brushes used to remove oil and wax, and reanimated the statues.

ROMA ARCHEOLOGICA & RESTAURO ARCHITETTURA 2021. "Send in the Bugs. The Michelangelos Need Cleaning" [= Laboratori Enea i batteri 'restauratori' per riparare dipinti, affreschi e statue], NYT (31 May, 2021): C1. S.v., ADNKRONOS / ARTE (10/04/2015).

“Come and see,” Bietti said, pointing, Creation-of-Adam-style, at the toe of Night.

But the cleaner the chapel became, the more the stubbornly marred the sarcophagus of Lorenzo di Piero stood out as an eyesore.

In 2016, Vincenti, one of the restorers, attended a conference held by Sprocati and her biologists. (“An introduction to the world of microorganisms,” Sprocati called it.) They showed how bacteria had cleaned up some resin residues on Baroque masterpiece frescoes in the Carracci Gallery at Palazzo Farnese in Rome. Strains isolated from mine drainage waters in Sardinia eliminated corrosive iron stains in the gallery’s Carrara marble.

When it came time to clean the Michelangelos, Vincenti pushed for a bacterial assist.

“I said, ‘OK,” said D’Agostino. “‘But let’s do a test first.’”

The bacteria passed the exam and did the job. On Monday, tourists admired the downward pensive glance of Michelangelo’s bearded Dusk, the rising of his groggy Dawn and Lorenzo’s tomb, now rid of the remnants of Alessandro.

“It’s very strange, especially in this time of Covid,” Marika Tapuska, a Slovakian visiting Florence with her family said when she learned that bacteria had cleaned up the sarcophagus. “But if it works, why not?”

Fonte / source, foto:
— NYT (31 May, 2021): C1.
https://www.nytimes.com/2021/05/30/arts/bacteria-cleaning-michelangelo-medici-restoration.html

ROMA ARCHEOLOGICA & RESTAURO ARCHITETTURA 2021. "Send in the Bugs. The Michelangelos Need Cleaning" [= Laboratori Enea i batteri 'restauratori' per riparare dipinti, affreschi e statue], NYT (31 May, 2021): C1. S.v., ADNKRONOS / ARTE (10/04/2015).

2). ROMA – S.v., ‘Roma, Casina Farnese sul Palatino’, in: “Arte: dai laboratori Enea i batteri ‘restauratori’ per riparare dipinti, affreschi e statue.” ADNKRONOS / ARTE (10/04/2015).

Presto su opere custodite in Vaticano l’applicazione dell’innovativa tecnica made in Italy messa a punto dal team coordinato da Anna Rosa Sprocati che all’Adnkronos spiega: “Tecnica a basso costo e con molti vantaggi.”

Batteri per restaurare statue, dipinti, affreschi, antichi manoscritti. Piccolissimi organismi che si nutrono in maniera selettiva delle scorie da rimuovere dalle opere e che agiscono come e meglio di un solvente senza però essere aggressivi né per l’oggetto da trattare, né per la salute degli addetti ai lavori.

E’ il biorestauro, la tecnica tutta italiana messa a punto dai ricercatori dell’Enea che verrà a breve applicata in Vaticano per il restauro della ‘Madonna della Cintola’, dipinto su legno, e per riparare i danni su statue e fontane che si trovano nei giardini della Santa Sede. Si tratta di una tecnica molto promettente. Finora infatti il laboratorio Enea ha selezionato ben 500 ceppi di batteri capaci di intervenire in diverse situazioni e su molteplici materiali.

Sprocati,
“Abbiamo isolato questi microrganismi e li abbiamo classificati in base a ciò che sono in grado di fare – spiega all’Adnkronos Anna Rosa Sprocati, coordinatrice del laboratorio Enea di Microbiologia ambientale e biotecnologie microbiche – creando poi una nostra banca dati. In base agli interventi che ci vengono richiesti dagli esperti, selezioniamo quindi in laboratorio i batteri più adatti, li sperimentiamo e li applichiamo per ‘aggredire’ determinate sostanze senza danneggiare le opere trattate”.

E la tecnica presenta diversi vantaggi: è a basso costo “perché – assicura la ricercatrice – crescere dei batteri su larga scala non implica davvero grandi spese”, non pone problemi etici perché si basa su organismi naturali non modificati geneticamente, è di facile applicazione e non è dannoso per la salute dei tecnici.

“Questo tipo di approccio – sottolinea Sprocati – interviene quando le tecniche tradizionali non sono soddisfacenti o quando per esserlo necessitano di prodotti aggressivi per le opere o tossici per i restauratori”. Sono proprio i restauratori infatti a beneficiare maggiormente della biotecnologia e a vedere nella sua applicazione un’alternativa promettente all’impiego dei tradizionali prodotti chimici. “L’uso dei batteri non è sostitutivo del lavoro degli esperti – tiene infatti a sottolineare la scienziata – ma ne costituisce uno strumento di lavoro. Noi – spiega – ci basiamo molto proprio sulle indicazioni che arrivano dai restauratori che ci chiedono aiuto. Senza il loro occhio del resto, spesso non ci sarebbe facile verificare l’efficacia di un trattamento”.

Il tempo di un restauro fatto dai batteri varia a seconda del tipo di intervento. “Può bastare una notte – dice Sprocati – come nel caso di una crosta nera da rimuovere da una statua, o possono essere necessarie diverse applicazioni come è capitato per rimuovere i residui di smog dalla ‘Lupa’ di Giuseppe Graziosi custodita alla Galleria nazionale di arte moderna e rimasta all’aperto per 40 anni”.

Diversi gli interventi di biorestauro richiesti agli scienziati Enea. Dalla Casina Farnese sul Palatino “dove abbiamo applicato diversi tipi di batteri in successione – spiega la ricercatrice – per rimuovere i residui dagli affreschi delle logge”, alla soluzione trovata ma non ancora applicata agli affreschi del Palazzo dei Papi di Avignone, in Francia. “In questo caso il problema era rimuovere della colla vinilica che tra gli anni Venti e Settanta è stata spalmata sugli affreschi per consolidarli – spiega Sprocati – ma col passare del tempo questa colla ha creato un film opaco. Con il restauro tradizionale bisognerebbe ricorrere a solventi che rischierebbero di danneggiare i dipinti. Noi invece abbiamo individuato due ceppi di batteri in grado di mangiare il vinavil senza intaccare l’opera”.

Fonte / source, foto:
— ADNKRONOS / ARTE (10/04/2015).
https://www.adnkronos.com/batteri-al-posto-dei-solventi-dallenea-la-soluzione-bio-per-il-restauro_6njbwG68AVoQaMQGt3Ppi6